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113-655: Despite pockets of agriculture, the islands are unnaturally barren due to wanton deforestation and the disappearance of the native olive groves, juniper and carob plantations. Fifty years ago much of the landscape was farmland bounded by dry stone walls but today, the local economy is based on sponge fishing and canning, supplemented by tourism in Lampedusa. The Pelagie Islands have been recognised as an Important Bird Area (IBA) by BirdLife International because they support breeding populations of Scopoli's shearwaters and European shags . Of particular ecological concern in

226-833: A 3.2% rise in global deforestation. Massive wildfires in Canada , exacerbated by climate change , contributed to a 24% increase in global tree cover loss, highlighting the ongoing threats to forests essential for carbon storage and biodiversity . Despite some progress, the overall trends in forest destruction and climate impacts remain off track. The IPCC Sixth Assessment Report stated in 2022: “Over 420 million ha of forest were lost to deforestation from 1990 to 2020; more than 90% of that loss took place in tropical areas (high confidence), threatening biodiversity, environmental services, livelihoods of forest communities and resilience to climate shocks (high confidence).” See also: Global deforestation sharply accelerated around 1852. As of 1947,

339-539: A biological advantage. Weeds also undergo the same acceleration of cycles as cultivated crops , and would also benefit from CO 2 fertilization . Since most weeds are C3 plants , they are likely to compete even more than now against C4 crops such as corn. The increased CO 2 levels are also expected to increase the tolerance of weeds to herbicides , reducing their efficiency. However, this may be counteracted by increased temperatures elevating their effectiveness. Currently, pathogens result in losses of 10–16% of

452-417: A decrease in minerals, evidence shows that plants contain 6% more carbon, 15% less nitrogen, 9% less phosphorus, and 9% less sulfur at double CO 2 conditions. The increase in carbon is mostly attributed to carbohydrates without a structural role in plants – the human-digestable, calorie-providing starch and simple sugars. The decrease in nitrogen translates directly into a decrease in the protein content. As

565-660: A larger number of crops than previously studied. It found that crop yields across Europe, sub-Saharan Africa, and Australia had in general decreased because of climate change (compared to the baseline value of 2004–2008 average data), though exceptions are present. The effect of global climate change on yields of different crops from climate trends ranged from −13.4% (oil palm) to 3.5% (soybean). The study also showed that effects are generally positive in Latin America. Effects in Asia and Northern and Central America are mixed. While

678-446: A loss. For example, a 1979 greenhouse study found that with doubled CO 2 concentration the dry weight of 40-day-old cotton plants doubled, but the dry weight of 30-day-old maize plants increased by only 20%. Changes in atmospheric carbon dioxide may reduce the nutritional quality of some crops, with for instance wheat having less protein and less of some minerals. The nutritional quality of C3 plants (e.g. wheat, oats, rice)

791-439: A matter of days, devastating farmers and costing billions in agricultural losses. Change in weather patterns and temperature due to climate change leads to dispersal of plant pathogens as hosts migrate to areas with more favourable conditions. This increases crop losses due to diseases. For instance, aphids act as vectors for many potato viruses and will be able to spread further due to increased temperatures. According to

904-524: A necessity for livestock production in the Caribbean. At 2.5 °C (4.5 °F), only layer hens would avoid daily exposure to "very severe" heat stress during the winter months. Both droughts and floods contribute to decreases in crop yields . On average, climate change increases the overall amount of water contained in the atmosphere by 7% per every 1 °C (1.8 °F), thus increasing precipitation . However, this increase in precipitation

1017-488: A paper which used an ensemble of 21 climate models estimated that under the most intense climate change scenario used at the time, RCP8.5 , global yields of these four crops would decline by between 3–12% around 2050 and by 11–25% by the year 2100. The losses were concentrated in what are currently the major agricultural producers and exporters. For instance, even by 2050, some agricultural areas of Australia , Brazil , South Africa , Southeast China , Southern Europe and

1130-477: A result of stomatal closing. The CO 2 fertilization effect or carbon fertilization effect causes an increased rate of photosynthesis while limiting leaf transpiration in plants. Both processes result from increased levels of atmospheric carbon dioxide (CO 2 ). The carbon fertilization effect varies depending on plant species, air and soil temperature, and availability of water and nutrients. Net primary productivity (NPP) might positively respond to

1243-436: A result, higher CO 2 not only reduce a plant's micronutrients, but also the quality of its macronutrient combination. Anthropogenic methane emissions have a significant contribution to warming due to the high global warming potential of methane. At the same time, methane also acts as a precursor to surface ozone , which is a significant air pollutant . Its effects include lowering physiological functions and therefore

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1356-444: Is water scarcity , which results in crop failures and the loss of pasture grazing land for livestock, exacerbating pre-existing poverty in developing countries and leading to malnutrition and potentially famine . Irrigation of crops is able to reduce or even remove the effects on yields of lower rainfall and higher temperatures – through localized cooling.  However, using water resources for irrigation has downsides and

1469-407: Is agreement that destruction of rainforests remains a significant environmental problem. The rate of net forest loss declined from 7.8 million ha per year in the decade 1990–2000 to 5.2 million ha per year in 2000–2010 and 4.7 million ha per year in 2010–2020. The rate of decline of net forest loss slowed in the most recent decade due to a reduction in the rate of forest expansion. In many parts of

1582-432: Is also a C4 carbon fixation plant, meaning that it experiences little benefit from the increased CO 2 levels. When the results from modelling experiments comparing the combined output of latest earth system models and dedicated agricultural crop models were published in 2021, the most notable new finding was the substantial reduction in projected global yields of maize. While the previous generation suggested that under

1695-584: Is also expected to elevate food safety issues and food spoilage caused by mycotoxin -producing fungi, and bacteria such as Salmonella . Climate change would cause an increase in rainfall in some areas, which would lead to an increase of atmospheric humidity and the duration of the wet seasons . Combined with higher temperatures, these conditions could favour the development of fungal diseases, such as late blight , or bacterial infections such as Ralstonia solanacearum , which may also be able to spread more easily through flash flooding . Climate change has

1808-758: Is around 38%. Since 1960, roughly 15% of the Amazon has been removed with the intention of replacing the land with agricultural practices. It is no coincidence that Brazil has recently become the world's largest beef exporter at the same time that the Amazon rainforest is being clear cut. Another prevalent method of agricultural deforestation is slash-and-burn agriculture , which was primarily used by subsistence farmers in tropical regions but has now become increasingly less sustainable. The method does not leave land for continuous agricultural production but instead cuts and burns small plots of forest land which are then converted into agricultural zones. The farmers then exploit

1921-399: Is covered by forests at present. This is one-third less than the forest cover before the expansion of agriculture, with half of that loss occurring in the last century. Between 15 million to 18 million hectares of forest, an area the size of Bangladesh , are destroyed every year. On average 2,400 trees are cut down each minute. Estimates vary widely as to the extent of deforestation in

2034-421: Is defined as the conversion of forest to other land uses (regardless of whether it is human-induced). Deforestation and forest area net change are not the same: the latter is the sum of all forest losses (deforestation) and all forest gains (forest expansion) in a given period. Net change, therefore, can be positive or negative, depending on whether gains exceed losses, or vice versa. The FAO estimates that

2147-469: Is especially at risk: lower levels of protein as well as minerals (for example zinc and iron) are expected. Food crops could see a reduction of protein , iron and zinc content in common food crops of 3 to 17%. This is the projected result of food grown under the expected atmospheric carbon-dioxide levels of 2050. Using data from the UN Food and Agriculture Organization as well as other public sources,

2260-605: Is estimated that some 420 million hectares of forest have been lost through conversion to other land uses , although the rate of deforestation has decreased over the past three decades. Between 2015 and 2020, the rate of deforestation was estimated at 10 million hectares per year, down from 16 million hectares per year in the 1990s. The area of primary forest worldwide has decreased by over 80 million hectares since 1990. More than 100 million hectares of forests are adversely affected by forest fires, pests, diseases, invasive species , drought and adverse weather events. Deforestation

2373-533: Is expected that these highly invasive crop pests will spread to other parts of the planet since they have a high capacity to adapt to different environments. A changing climate may favour the more biologically diverse weeds over the monocrops on many farms. Characteristics of weeds such as their genetic diversity , cross-breeding ability, and fast-growth rates put them at an advantage in changing climates as these characteristics allow them to adapt readily in comparison to most farm's uniform crops, and give them

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2486-478: Is expected to decrease in the second half of the century, and with greater effect in tropical than temperate regions. There is a large number of agricultural crops , but not all of them are equally important. Most climate change assessments focus on "four major crops" – maize (corn), rice , wheat and soybeans – which are consumed directly and indirectly, as animal feed (the main purpose of soybeans). The three cereals are collectively responsible for half of

2599-733: Is expected to drive some improvements on its own. Further, agricultural expansion has slowed down in the recent years, but this trend is widely expected to reverse in the future in order to maintain the global food supply under all but the most optimistic climate change scenarios consistent with the Paris Agreement . In 2007, the IPCC Fourth Assessment Report had suggested that global production potential would increase up to around 3 °C (5.4 °F) of globally averaged warming, as productivity increases for cereals in high latitudes would outweigh decreases in

2712-403: Is expected to increase overall thermal comfort for humans living in the colder regions of the world, livestock in those places would also benefit from warmer winters. Across the entire world, however, increasing summertime temperatures as well as more frequent and intense heatwaves will have clearly negative effects, substantially elevating the risk of livestock suffering from heat stress . Under

2825-408: Is expensive. Further, some sources of irrigation water may become less reliable. This includes irrigation driven by water runoff from glaciers during the summer, as there has already been an observed retreat of glaciers since 1850 , and it is expected to continue, depleting the glacial ice and reducing or outright eliminating runoff. In Asia, global warming of 1.5 °C (2.7 °F) will reduce

2938-605: Is not an issue because of longer fallow periods and lesser overall deforestation. The relatively small size of the plots allowed for no net input of CO 2 to be released. Consumption and production of beef is the primary driver of deforestation in the Amazon , with around 80% of all converted land being used to rear cattle. 91% of Amazon land deforested since 1970 has been converted to cattle ranching. Livestock ranching requires large portions of land to raise herds of animals and livestock crops for consumer needs. According to

3051-438: Is not distributed evenly in space ( atmospheric circulation patterns already cause different areas to receive different amounts of rainfall) or time: heavy rainfall, with the potential to cause floods, becomes more frequent. This means that under the probable mid-range climate change scenario , SSP2-4.5, precipitation events globally will become larger by 11.5%, yet the time between them will increase by an average of 5.1%. Under

3164-457: Is often considered unrealistic, and a less intense RCP4.5 scenario (which still leads to nearly 3 °C (5.4 °F) by century's end, far in excess of the Paris Agreement goals) is now usually considered a better match for the current trajectory. Out of the four crops, maize is considered the most vulnerable to warming, with one meta-analysis concluding that every 1 °C (1.8 °F) of global warming reduces maize yields by 7.4%. It

3277-569: Is often difficult. Exceptions include West Africa , where the climate-induced intensification of extreme weather was found to have already decreased millet yields by 10–20%, and sorghum yields 5–15%. Similarly, it was found that climate change had intensified drought conditions in Southern Africa in 2007, which elevated food prices and caused "acute food insecurity" in the country of Lesotho . Agriculture in Southern Africa

3390-453: Is projected to occur by the mid-21st century. In the early 2000s, some scientists predicted that unless significant measures (such as seeking out and protecting old growth forests that have not been disturbed) are taken on a worldwide basis, by 2030 there will only be 10% remaining, with another 10% in a degraded condition . 80% will have been lost, and with them hundreds of thousands of irreplaceable species. Estimates vary widely as to

3503-727: Is responsible for 48% of deforestation; commercial agriculture is responsible for 32%; logging is responsible for 14%, and fuel wood removals make up 5%. More than 80% of deforestation was attributed to agriculture in 2018. Forests are being converted to plantations for coffee, tea, palm oil , rice, rubber , and various other popular products. The rising demand for certain products and global trade arrangements causes forest conversions , which ultimately leads to soil erosion . The top soil oftentimes erodes after forests are cleared which leads to sediment increase in rivers and streams. Most deforestation also occurs in tropical regions. The estimated amount of total land mass used by agriculture

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3616-461: Is that deforestation reduces the uptake of carbon dioxide ( carbon sequestration ) from the atmosphere. This reduces the potential of forests to assist with climate change mitigation . The role of forests in capturing and storing carbon and mitigating climate change is also important for the agricultural sector. The reason for this linkage is because the effects of climate change on agriculture pose new risks to global food systems . Since 1990, it

3729-414: Is that temperatures will increase and precipitation will decrease in arid and semi-arid regions ( Middle East , Africa , Australia , Southwest United States , and Southern Europe ). In addition, crop yields in tropical regions will be negatively affected by the projected moderate increase in temperature (1–2 °C) expected to occur during the first half of the century. During the second half of

3842-461: The 2020–2023 Horn of Africa drought has been primarily attributed to the great increase in evotranspiration exacerbating the effect of persistent low rainfall, which would have been more manageable in the cooler preindustrial climate. In total, this means that droughts have been occurring more frequently on average because of climate change. Africa, southern Europe, the Middle East, most of

3955-560: The Congolese rainforest increased by 5%. The World Wildlife Fund 's ecoregion project catalogues habitat types throughout the world, including habitat loss such as deforestation, showing for example that even in the rich forests of parts of Canada such as the Mid-Continental Canadian forests of the prairie provinces half of the forest cover has been lost or altered. In 2011, Conservation International listed

4068-509: The El Nino weather conditions, while 2003 European heat wave led to 13 billion euros in uninsured agriculture losses. Climate change is known to increase the frequency and severity of heatwaves , and to make precipitation less predictable and more prone to extremes, but since climate change attribution is still a relatively new field, connecting specific weather events and the shortfalls they cause to climate change over natural variability

4181-629: The Green Revolution had ensured the growth of overall crop production per land area of 250% to 300% since the 1960, with around 44% attributed to newer crop varieties alone, it is believed this growth would have been even greater without the counteracting role of climate change on major crop yields over the same period. Between 1961 and 2021, global agricultural productivity could have been 21% greater than it actually was, if it did not have to contend with climate change. Such shortfalls would have affected food security of vulnerable populations

4294-566: The IPCC Sixth Assessment Report from 2022, there is high confidence that in and of itself, climate change to date has left primarily negative effects on both crop yields and quality of produce, although there has been some regional variation: more negative effects have been observed for some crops in low-latitudes (maize and wheat), while positive effects of climate change have been observed in some crops in high-latitudes (maize, wheat, and sugar beets ). I.e. during

4407-474: The Mediterranean became more affected by drought . Similarly, the severity of heatwave and drought effects on European crop production was found to have tripled over a 50-year period – from losses of 2.2% during 1964–1990 to losses of 7.3% in 1991–2015. In the summer of 2018, heat waves probably linked to climate change greatly reduced average yield in many parts of the world, especially Europe. During

4520-849: The Mountain Pine Beetle epidemic in British Columbia , Canada had killed millions of pine trees, partially because the winters were not cold enough to slow or kill the growing beetle larvae. Likewise, potato tuber moth and Colorado potato beetle are predicted to spread into areas currently too cold for them. Further, effects of climate change on the water cycle often mean that both wet seasons and drought seasons will become more intense. Some insect species will breed more rapidly because they are better able to take advantage of such changes in conditions. This includes certain insect pests, such as aphids and whiteflies : similarly, locust swarms could also cause more damage as

4633-730: The Philippines , Indonesia , Thailand , Burma , Malaysia , Bangladesh , China, Sri Lanka , Laos , Nigeria , the Democratic Republic of the Congo , Liberia , Guinea , Ghana and the Ivory Coast , have lost large areas of their rainforest. Much of what remains of the world's rainforests is in the Amazon basin , where the Amazon Rainforest covers approximately 4 million square kilometres. Some 80% of

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4746-495: The United States would suffer production losses of mostly maize and soybeans exceeding 25%. A similar finding - that some major "breadbaskets" would begin to see unequivocal effects of climate change, both positive and negative, before the year 2040 - had been established in another study from the same year. Since it represents the worst-case scenario of continually increasing emissions with no efforts to reduce them, RCP8.5

4859-479: The World Wildlife Fund , "Extensive cattle ranching is the number one culprit of deforestation in virtually every Amazon country, and it accounts for 80% of current deforestation." The cattle industry is responsible for a significant amount of methane emissions since 60% of all mammals on earth are livestock cows. Replacing forest land with pastures creates a loss of forest stock , which leads to

4972-534: The climate change scenario of highest emissions and greatest warming, SSP5-8.5 , "cattle,sheep, goats, pigs and poultry in the low latitudes will face 72–136 additional days per year of extreme stress from high heat and humidity". In Jamaica , considered representative of the Caribbean region, all livestock animals besides layer hens are already exposed to "very severe" heat stress in the present climate, with pigs being exposed to it at least once per day during

5085-454: The ecosystem processes associated with the CO 2 fertilization effect remain uncertain and therefore are challenging to model. A 1993 review of scientific greenhouse studies found that a doubling of CO 2 concentration would stimulate the growth of 156 different plant species by an average of 37%. Response varied significantly by species, with some showing much greater gains and a few showing

5198-412: The metabolic rate and number of breeding cycles of insect populations. Historically, cold temperatures at night and in the winter months would kill off insects , bacteria and fungi . The warmer, wetter winters are promoting fungal plant diseases like wheat rusts ( stripe and brown/leaf ) and soybean rust to travel northward. The increasing incidence of flooding and heavy rains also promotes

5311-412: The soil microbe population size to dramatically increase 40–150%. Warmer conditions would favour growth of certain bacteria species, shifting the bacterial community composition. Elevated carbon dioxide would increase the growth rates of plants and soil microbes, slowing the soil carbon cycle and favouring oligotrophs , which are slower-growing and more resource efficient than copiotrophs . A rise in

5424-577: The tropics . In 2019, nearly a third of the overall tree cover loss, or 3.8 million hectares, occurred within humid tropical primary forests . These are areas of mature rainforest that are especially important for biodiversity and carbon storage . The direct cause of most deforestation is agriculture by far. More than 80% of deforestation was attributed to agriculture in 2018. Forests are being converted to plantations for coffee , palm oil , rubber and various other popular products. Livestock grazing also drives deforestation. Further drivers are

5537-574: The wood industry ( logging ), urbanization and mining . The effects of climate change are another cause via the increased risk of wildfires (see deforestation and climate change ). Deforestation results in habitat destruction which in turn leads to biodiversity loss . Deforestation also leads to extinction of animals and plants, changes to the local climate, and displacement of indigenous people who live in forests. Deforested regions often also suffer from other environmental problems such as desertification and soil erosion . Another problem

5650-429: The 5 summer and early autumn months, while ruminants and broilers only avoid daily exposure to very severe heat stress during the winter. it has been projected that even at 1.5 °C (2.7 °F) of global warming, "very severe" heat stress would become a daily event for ruminants and broilers . By 2 °C (3.6 °F), it would be felt for a longer duration, and extensive cooling systems would likely become

5763-470: The Americas, Australia, South and Southeast Asia are the parts of the globe where droughts are expected to become more frequent and intense in spite of the global increase in precipitation. Droughts disturb terrestrial precipitation, evaporation and soil moisture , and these effects can be aggravated by population growth and urban expansion spurring on increased demand for water. The ultimate outcome

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5876-542: The CO 2 fertilization effect (6.5±1.0%). The warmer atmospheric temperatures observed over the past decades are expected to lead to a more vigorous hydrological cycle, including more extreme rainfall events. Erosion and soil degradation is more likely to occur. Soil fertility would also be affected by global warming. Increased erosion in agricultural landscapes from anthropogenic factors can occur with losses of up to 22% of soil carbon in 50 years. Climate change will also cause soils to warm. In turn, this could cause

5989-408: The CO 2 levels expected in the second half of the 21st century will likely reduce the levels of zinc, iron, and protein in wheat, rice, peas, and soybeans. Some two billion people live in countries where citizens receive more than 60 per cent of their zinc or iron from these types of crops. Deficiencies of these nutrients already cause an estimated loss of 63 million life-years annually. Alongside

6102-609: The activity of pollinators , threatening their reproductive success. In the longer term, however, they would result in longer growing seasons . For example, a 2014 study found that maize yields in the Heilongjiang region of China increased by between 7 and 17% per decade as a result of rising temperatures. On the other hand, a year 2017 meta-analysis comparing data from four different methods of estimating effect of warming (two types of climate model, statistical regressions and field experiments where land around certain crops

6215-460: The agricultural sector of Belgium, one of the countries hardest hit by the floods, including long-term effects like soil erosion . In China , 2023 research found that extreme rainfall had cost the country about 8% of its rice output over the two preceding decades. This was considered comparable to losses caused by extreme heat over this period. Changes in temperature and weather patterns will alter areas suitable for farming. The current prediction

6328-881: The authors analysed 225 different staple foods, such as wheat , rice , maize , vegetables , roots and fruits . The effect of increased levels of atmospheric carbon dioxide on the nutritional quality of plants is not limited only to the above-mentioned crop categories and nutrients. A 2014 meta-analysis has shown that crops and wild plants exposed to elevated carbon dioxide levels at various latitudes have lower density of several minerals such as magnesium, iron, zinc, and potassium. Studies using Free-Air Concentration Enrichment have also shown that increases in CO 2 lead to decreased concentrations of micronutrients in crop and non-crop plants with negative consequences for human nutrition, including decreased B vitamins in rice. This may have knock-on effects on other parts of ecosystems as herbivores will need to eat more food to gain

6441-416: The capability of altering pathogen and host interactions, specifically the rates of pathogen infection and the resistance of the host plant. Also affected by plant disease are the economic costs associated with growing different plants that might yield less profit as well as treating and managing already diseased crops. For instance, soybean rust is a vicious plant pathogen that can kill off entire fields in

6554-542: The carbon fertilization effect. Although, evidence shows that enhanced rates of photosynthesis in plants due to CO 2 fertilization do not directly enhance all plant growth, and thus carbon storage. The carbon fertilization effect has been reported to be the cause of 44% of gross primary productivity (GPP) increase since the 2000s. Earth System Models , Land System Models and Dynamic Global Vegetation Models are used to investigate and interpret vegetation trends related to increasing levels of atmospheric CO 2 . However,

6667-565: The century, further warming is projected to decrease crop yields in all regions including Canada and the Northern United States . Many staple crops are extremely sensitive to heat and when temperatures rise over 36 °C (97 °F), soybean seedlings are killed and corn pollen loses its vitality. Higher winter temperatures and more frost-free days in some regions can currently be disruptive, as they can cause phenological mismatch between flowering time of plants and

6780-642: The commodity is consumed. For example, consumption patterns in G7 countries are estimated to cause an average loss of 3.9 trees per person per year. In other words, deforestation can be directly related to imports—for example, coffee. In 2023, the Global Forest Watch reported a 9% decline in tropical primary forest loss compared to the previous year, with significant regional reductions in Brazil and Colombia overshadowed by increases elsewhere, leading to

6893-522: The concentration of saltwater exceeds 2–3%, the well becomes unusable. Notably, areas along an estimated 15% of the US coastline already have the majority of local groundwater below the sea level. Climate change may increase the amount of arable land by reducing the amount of frozen land. A 2005 study reports that temperature in Siberia has increased three-degree Celsius in average since 1960 (much more than

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7006-478: The country's western regions at a rate of 15,000 hectares at a randomly studied 2-month period in 2010. In 2009, Paraguay's parliament refused to pass a law that would have stopped cutting of natural forests altogether. As of 2007, less than 50% of Haiti's forests remained . From 2015 to 2019, the rate of deforestation in the Democratic Republic of the Congo doubled. In 2021, deforestation of

7119-408: The crops. Furthermore, CO 2 fertilization has little effect on C4 crops like maize . On the coasts, some agricultural land is expected to be lost to sea level rise , while melting glaciers could result in less irrigation water being available. On the other hand, more arable land may become available as frozen land thaws. Other effects include erosion and changes in soil fertility and

7232-780: The decades 1990–2000 and 2000–2010. Some claim that rainforests are being destroyed at an ever-quickening pace. The London-based Rainforest Foundation notes that "the UN figure is based on a definition of forest as being an area with as little as 10% actual tree cover, which would therefore include areas that are actually savanna-like ecosystems and badly damaged forests". Other critics of the FAO data point out that they do not distinguish between forest types, and that they are based largely on reporting from forestry departments of individual countries, which do not take into account unofficial activities like illegal logging. Despite these uncertainties, there

7345-498: The deforestation of the Amazon can be attributed to cattle ranching, as Brazil is the largest exporter of beef in the world. The Amazon region has become one of the largest cattle ranching territories in the world. The regions with the highest tropical deforestation rate between 2000 and 2005 were Central America —which lost 1.3% of its forests each year—and tropical Asia. In Central America , two-thirds of lowland tropical forests have been turned into pasture since 1950 and 40% of all

7458-519: The end of the century. Vietnam for example relies heavily on its southern tip, where the Mekong Delta lies, for rice planting. A one-metre rise in sea level will cover several square kilometres of rice paddies in Vietnam. Besides simply flooding agricultural land, sea level rise can also cause saltwater intrusion into freshwater wells , particularly if they are already below sea level. Once

7571-463: The extent of deforestation in the tropics. In 2019, the world lost nearly 12 million hectares of tree cover. Nearly a third of that loss, 3.8 million hectares, occurred within humid tropical primary forests, areas of mature rainforest that are especially important for biodiversity and carbon storage. This is equivalent to losing an area of primary forest the size of a football pitch every six seconds. A 2002 analysis of satellite imagery suggested that

7684-445: The foreseeable future. The future degree of soil erosion and groundwater depletion are further uncertainties. On the other hand, a range of improvements to agricultural yields, collectively known as the Green Revolution , has increased yields per unit of land area by between 250% and 300% since 1960. Some of that progress will likely continue. The scientific consensus is that global food security will change relatively little in

7797-432: The form of charcoal or timber ), while cleared land is used as pasture for livestock and agricultural crops. The vast majority of agricultural activity resulting in deforestation is subsidized by government tax revenue . Disregard of ascribed value, lax forest management , and deficient environmental laws are some of the factors that lead to large-scale deforestation. The types of drivers vary greatly depending on

7910-541: The future (to 2100 and beyond) are rare. There is some concern about the effects on food security from more extreme weather events in future. Nevertheless, at this stage there is no expectation of a widespread global famine due to climate change within the 21st century. Agriculture is sensitive to weather, and major events like heatwaves or droughts or heavy rains (also known as low and high precipitation extremes) can cause substantial losses. For example, Australia 's farmers are very likely to suffer losses during

8023-568: The global forest carbon stock has decreased 0.9%, and tree cover 4.2% between 1990 and 2020. As of 2019 there is still disagreement about whether the global forest is shrinking or not: "While above-ground biomass carbon stocks are estimated to be declining in the tropics, they are increasing globally due to increasing stocks in temperate and boreal forest. Deforestation in many countries —both naturally occurring and human-induced —is an ongoing issue. Between 2000 and 2012, 2.3 million square kilometres (890,000 square miles) of forests around

8136-410: The global harvest and this level is likely to rise as plants are at an ever-increasing risk of exposure to pests and pathogens . Research has shown that climate change may alter the developmental stages of plant pathogens that can affect crops. This includes several pathogens associated with potato blackleg disease (e.g. Dickeya ), as they grow and reproduce faster at higher temperatures. The warming

8249-456: The growth of various other plant pests and diseases. Climate change is expected to have a negative effect on many insects, greatly reducing their species distribution and thus increasing their risk of going extinct . Around 9% of agricultural production is dependent in some way on insect pollination , and some pollinator species are also adversely affected, with wild bumblebees known to be particularly vulnerable to recent warming. At

8362-411: The highest-emission scenario SSP5-8.5 , there will be an 18.5% increase in size of events and 9.6% increase in the duration between them. At the same time, water losses by plants through evotranspiration will increase almost everywhere due to higher temperatures. While the CO 2 fertilization effect also reduces such losses by plants, it depends on the area's climate which effect will dominate. As such,

8475-595: The ice mass of Asia's high mountains by about 29–43%,: Approximately 2.4 billion people live in the drainage basin of the Himalayan rivers: In India alone, the river Ganges provides water for drinking and farming for more than 500 million people. In the Indus River watershed, these mountain water resources contribute to up to 60% of irrigation outside of the monsoon season, and an additional 11% of total crop production. Since Effects of climate change on

8588-402: The implication of increased greenhouse gas emissions by burning agriculture methodologies and land-use change . A large contributing factor to deforestation is the lumber industry . A total of almost 4 million hectares (9.9 million acres) of timber, or about 1.3% of all forest land, is harvested each year. In addition, the increasing demand for low-cost timber products only supports

8701-601: The islands is the protection of the loggerhead sea turtle ( Caretta caretta ) which is endangered throughout the Mediterranean as a result of its nesting sites being taken over by tourism. In Italy the beaches of Pozzolana di Ponente on Linosa and Isola dei conigli on Lampedusa are two of the last remaining sites where the turtle regularly lays its eggs, the others (larger) being in southern Calabria (close to Reggio Calabria ). The Area Marina Protetta Isole Pelagie nature reserve , covering all three islands,

8814-702: The largest annual rate of net forest loss in 2010–2020, at 3.9 million ha, followed by South America, at 2.6 million ha. The rate of net forest loss has increased in Africa in each of the three decades since 1990. It has declined substantially in South America, however, to about half the rate in 2010–2020 compared with 2000–2010. Asia had the highest net gain of forest area in 2010–2020, followed by Oceania and Europe. Nevertheless, both Europe and Asia recorded substantially lower rates of net gain in 2010–2020 than in 2000–2010. Oceania experienced net losses of forest area in

8927-662: The length of growing seasons. Also, bacteria like Salmonella and fungi that produce mycotoxins grow faster as the climate warms. Their growth has negative effects on food safety , food loss and prices . There has been extensive research on the effects of climate change on individual crops, particularly on the four staple crops : corn (maize), rice , wheat and soybeans . These crops are responsible for around two-thirds of all calories consumed by humans (both directly and indirectly as animal feed). The research investigates important uncertainties, for example future population growth , which will increase global food demand for

9040-525: The low latitudes and global aggregate yields of rain-fed agriculture would increase by 5–20% in the first half of the 21st century. Warming exceeding this level would very likely see global declines in yields. Since then, subsequent reports had been more negative on the global production potential. The US National Research Council assessed the literature on the effects of climate change on crop yields in 2011, and provided central estimates for key crops. A meta-analysis in 2014 revealed consensus that yield

9153-775: The lumber company to continue logging. Experts do not agree on whether industrial logging is an important contributor to global deforestation. Some argue that poor people are more likely to clear forest because they have no alternatives, others that the poor lack the ability to pay for the materials and labour needed to clear forest. Effects of climate change on agriculture There are numerous effects of climate change on agriculture , many of which are making it harder for agricultural activities to provide global food security . Rising temperatures and changing weather patterns often result in lower crop yields due to water scarcity caused by drought , heat waves and flooding . These effects of climate change can also increase

9266-430: The main driver of deforestation and forest fragmentation and the associated loss of forest biodiversity. Large-scale commercial agriculture (primarily cattle ranching and cultivation of soya bean and oil palm) accounted for 40 percent of tropical deforestation between 2000 and 2010, and local subsistence agriculture for another 33 percent. Trees are cut down for use as building material, timber or sold as fuel (sometimes in

9379-522: The month of August, more crop failures resulted in a rise in global food prices . On the other hand, floods, often linked to climate change, have also had notable adverse effects on agriculture in the recent years. In May 2019, floods shortened corn planting season in the Midwestern United States , lowering the projected yield from 15 billion bushels to 14.2. During the 2021 European floods , estimates pointed to severe damage to

9492-413: The most: a study in 2019 showed that climate change has already increased the risk of food insecurity in many food insecure countries. Even in developed countries such as Australia , extreme weather associated with climate change has been found to cause a wide range of cascading spillovers through supply chain disruption, in addition to its primary effect on fruit, vegetable, and livestock sectors and

9605-531: The near-term. 720 million to 811 million people were undernourished in 2021, with around 200,000 people being at a catastrophic level of food insecurity. Climate change is expected to add an additional 8 to 80 million people who are at risk of hunger by 2050. The estimated range depends on the intensity of future warming and the effectiveness of adaptation measures . Agricultural productivity growth will likely have improved food security for hundreds of millions of people by then. Predictions that reach further into

9718-460: The nutrients in the ashes of the burned plants. As well as, intentionally set fires can possibly lead to devastating measures when unintentionally spreading fire to more land, which can result in the destruction of the protective canopy. The repeated cycle of low yields and shortened fallow periods eventually results in less vegetation being able to grow on once burned lands and a decrease in average soil biomass. In small local plots sustainability

9831-566: The original 16 million square kilometres (6 million square miles) of tropical rainforest that formerly covered the Earth. More than 3.6 million hectares of virgin tropical forest was lost in 2018. The global annual net loss of trees is estimated to be approximately 10 billion. According to the Global Forest Resources Assessment 2020 the global average annual deforested land in the 2015–2020 demi-decade

9944-418: The other hand, a 2005 analysis of satellite images reveals that deforestation of the Amazon rainforest is twice as fast as scientists previously estimated. From 2010 to 2015, worldwide forest area decreased by 3.3 million ha per year, according to FAO . During this five-year period, the biggest forest area loss occurred in the tropics, particularly in South America and Africa. Per capita forest area decline

10057-400: The period 1981 to 2008, global warming has had negative effects on wheat yield in especially tropical regions, with decreases in average global yields by 5.5%.   A study in 2019 tracked ~20,000 political units globally for 10 crops ( maize , rice , wheat , soybean , barley , cassava , oil palm , rapeseed , sorghum and sugarcane ), providing more detail on the spatial resolution and

10170-410: The planet had 15 to 16 million km (5.8 to 6.2 million sq mi) of mature tropical forests , but by 2015, it was estimated that about half of these had been destroyed. Total land coverage by tropical rainforests decreased from 14% to 6%. Much of this loss happened between 1960 and 1990, when 20% of all tropical rainforests were destroyed. At this rate, extinction of such forests

10283-492: The rainforests have been lost in the last 40 years. Brazil has lost 90–95% of its Mata Atlântica forest. Deforestation in Brazil increased by 88% for the month of June 2019, as compared with the previous year. However, Brazil still destroyed 1.3 million hectares in 2019. Brazil is one of several countries that have declared their deforestation a national emergency. Paraguay was losing its natural semi-humid forests in

10396-472: The rate of deforestation in the humid tropics (approximately 5.8 million hectares per year) was roughly 23% lower than the most commonly quoted rates. A 2005 report by the United Nations Food and Agriculture Organization (FAO) estimated that although the Earth's total forest area continued to decrease at about 13 million hectares per year, the global rate of deforestation had been slowing. On

10509-476: The region in which they take place. The regions with the greatest amount of deforestation for livestock and row crop agriculture are Central and South America, while commodity crop deforestation was found mainly in Southeast Asia. The region with the greatest forest loss due to shifting agriculture was sub-Saharan Africa. The overwhelming direct cause of deforestation is agriculture. Subsistence farming

10622-609: The rest of the world). However, reports about the effect of global warming on Russian agriculture indicate conflicting probable effects: while they expect a northward extension of farmable lands, they also warn of possible productivity losses and increased risk of drought. The Arctic region is expected to benefit from increased opportunities for agriculture and forestry . Climate change will alter pest , plant disease and weed distributions, with potential to reduce crop yields, including of staple crops like wheat , soybeans , and corn (maize). Warmer temperatures can increase

10735-412: The result. A notable example was the 2019–2022 locust infestation focused on East Africa , considered the worst of its kind in many decades. The fall armyworm , Spodoptera frugiperda , is a highly invasive plant pest, which can cause have massive damage to crops, especially maize. In the recent years, it has spread to countries in sub-Saharan Africa , and this spread is linked to climate change. It

10848-410: The risk of several regions suffering simultaneous crop failures . Currently this risk is regarded as rare but if these simultaneous crop failures did happen they would have significant consequences for the global food supply. Many pests and plant diseases are also expected to either become more prevalent or to spread to new regions. The world's livestock are also expected to be affected by many of

10961-413: The rural communities reliant on them. Between 1961 and 1985, cereal production more than doubled in developing nations , largely due to the development of irrigation, fertilizer, and seed varieties. Even in the absence of further scientific/technological developments, many of the existing advancements have not been evenly distributed, and their spread from the developed world to the developing world

11074-401: The same amount of protein. Empirical evidence shows that increasing levels of CO 2 result in lower concentrations of many minerals in plant tissues. Doubling CO 2 levels results in an 8% decline, on average, in the concentration of minerals. Declines in magnesium, calcium, potassium, iron, zinc and other minerals in crops can worsen the quality of human nutrition. Researchers report that

11187-453: The same issues, from greater heat stress to animal feed shortfalls and the spread of parasites and vector-borne diseases . The increased atmospheric CO 2 level from human activities (mainly burning of fossil fuels ) causes a CO 2 fertilization effect . This effect offsets a small portion of the detrimental effects of climate change on agriculture. However, it comes at the expense of lower levels of essential micronutrients in

11300-443: The same time, insects are the most diverse animal taxa, and some species will benefit from the changes, including notable agricultural pests and disease vectors . Insects that previously had only two breeding cycles per year could gain an additional cycle if warm growing seasons extend, causing a population boom. Temperate places and higher latitudes are more likely to experience a dramatic change in insect populations: for instance,

11413-424: The sea level would result in an agricultural land loss , in particular in areas such as South East Asia . Erosion , submergence of shorelines , salinity of the water table due to the increased sea levels, could mainly affect agriculture through inundation of low-lying lands . Low-lying areas such as Bangladesh , India and Vietnam will experience major loss of rice crop if sea levels rise as expected by

11526-522: The size of India—by 2050. 36% of globally planted forest area is in East Asia – around 950,000 square kilometers. From those 87% are in China. Rates of deforestation vary around the world. Up to 90% of West Africa 's coastal rainforests have disappeared since 1900. Madagascar has lost 90% of its eastern rainforests. In South Asia , about 88% of the rainforests have been lost. Mexico , India ,

11639-467: The top 10 most endangered forests, characterized by having all lost 90% or more of their original habitat , and each harboring at least 1500 endemic plant species (species found nowhere else in the world). As of 2015 , it is estimated that 70% of the world's forests are within one kilometer of a forest edge, where they are most prone to human interference and destruction. Deforestation in particular countries: Agricultural expansion continues to be

11752-406: The total human calorie intake, and together with soybeans, they account for two thirds. Different methods have been used to project future yields of these crops, and by 2019, the consensus was that warming would lead to aggregate declines of the four. Maize and soybean would decrease with any warming, whereas rice and wheat production might peak at 3 °C (5.4 °F) of warming. In 2021,

11865-537: The water cycle are projected to substantially increase precipitation in all but the westernmost parts of the watershed, the loss of the glaciers is expected to be offset: however, agriculture in the region will become more reliable on monsoon than ever, and hydropower generation would become less predictable and reliable. Elevated atmospheric carbon dioxide affects plants in a variety of ways. Elevated CO 2 increases crop yields and growth through an increase in photosynthetic rate, and it also decreases water loss as

11978-473: The world were cut down. Deforestation and forest degradation continue to take place at alarming rates, which contributes significantly to the ongoing loss of biodiversity . Deforestation is more extreme in tropical and subtropical forests in emerging economies. More than half of all plant and land animal species in the world live in tropical forests . As a result of deforestation, only 6.2 million square kilometres (2.4 million square miles) remain of

12091-576: The world, especially in East Asian countries, reforestation and afforestation are increasing the area of forested lands. The amount of forest has increased in 22 of the world's 50 most forested nations. Asia as a whole gained 1 million hectares of forest between 2000 and 2005. Tropical forest in El Salvador expanded more than 20% between 1992 and 2001. Based on these trends, one study projects that global forestation will increase by 10%—an area

12204-451: The yield and quality of crops. Following methane levels, tropospheric ozone levels "increased substantially since the late 19th century", and according to a 2016 estimate, the four major crops (see later section) experienced yield losses of 5±1.5% relative to a no-climate change scenario due to ozone increases alone, which is nearly half of the negative effects caused by the other effects of climate change (10.9±3.2%), and cancels out most of

12317-456: Was 10 million hectares and the average annual forest area net loss in the 2000–2010 decade was 4.7 million hectares. The world has lost 178 million ha of forest since 1990, which is an area about the size of Libya. An analysis of global deforestation patterns in 2021 showed that patterns of trade, production, and consumption drive deforestation rates in complex ways. While the location of deforestation can be mapped, it does not always match where

12430-404: Was also adversely affected by drought after climate change intensified the effects of 2014–2016 El Niño event . In Europe , between 1950 and 2019, heat extremes have become more frequent and also more likely to occur consecutively, while cold extremes have declined. At the same time, Northern Europe and much of Eastern Europe was found to experience extreme precipitation more often, while

12543-461: Was also greatest in the tropics and subtropics but is occurring in every climatic domain (except in the temperate) as populations increase. An estimated 420 million ha of forest has been lost worldwide through deforestation since 1990, but the rate of forest loss has declined substantially. In the most recent five-year period (2015–2020), the annual rate of deforestation was estimated at 10 million ha, down from 12 million ha in 2010–2015. Africa had

12656-422: Was instituted in 2002. This Sicilian location article is a stub . You can help Misplaced Pages by expanding it . Deforestation Deforestation or forest clearance is the removal and destruction of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms , ranches , or urban use. About 31% of Earth's land surface

12769-503: Was warmed by a certain amount to compare them with the controls) concluded that on a global scale, warming alone has consistently negative effects on the yields of four most important crops, suggesting that any increases would be down to precipitation changes and the CO2 fertilization effect . In general, the preferred ambient temperature range for domestic animals is between 10 and 30 °C (50 and 86 °F). Much like how climate change

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