Rising global temperatures lead to widespread drought – Is it up because of that?

news7g09/28/2022

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Rising global temperatures lead to widespread drought - Is it up because of that?

The other Playstation model science or perhaps the new term should be virtual reality.-Cr

UNIVERSITY OF EAST ANGLIA

More frequent and prolonged droughts caused by rising global temperatures pose significant risks to people and ecosystems worldwide, according to new research from the University of East Anglia (UEA).

The study found that even a modest 1.5°C rise in temperature would have dire consequences in India, China, Ethiopia, Ghana, Brazil and Egypt. These six countries were selected for study in the UEA project because they provide a range of contrasting sizes and different levels of development across three continents spanning tropical and temperate biomes, as well as forest, grassland and desert habitats.

The findings, ‘Quantifying the 1.5°C to 4°C Meteorological Drought Risks of Global Warming in Six Countries’, were published today in the journal The climate changes.

The paper, led by Dr Jeff Price and his colleagues at the Tyndall Center for Climate Change Research at the UEA, quantified the expected effects of alternative levels of global warming on with the probability and length of severe drought in six countries.

Dr Price, Associate Professor of Biodiversity and Climate Change, said: “Current commitments to climate change mitigation, are projected to still lead to a global warming level of 3 °C or higher, will impact all countries in this study.

“For example, with 3°C warming, more than 50% of agricultural area in each country is projected to experience severe droughts lasting more than a year over a 30-year period.

“Using standard population projections, it is estimated that 80% to 100% of the population in Brazil, China, Egypt, Ethiopia and Ghana (and nearly 50% of the Indian population) are projected to be confined drought lasting one year or more over a 30-year period.

“In contrast, we find that meeting the long-term temperature target of the Paris Agreement, which is to limit warming to 1.5°C above pre-industrial levels, is forecast to be beneficial. enormous benefit to all of the countries in this study, significantly reducing exposure to severe drought for a large proportion of the population and in all major land covers, of which Egypt is likely to benefit the most”.

In the 1.5°C warming scenario, the probability of drought is projected to triple in Brazil and China, nearly double in Ethiopia and Ghana, increase slightly in India, and increase significantly in Egypt.

In the 2°C warming scenario, the probability of drought is forecast to increase 4 times in Brazil and China; doubled in Ethiopia and Ghana; reaching a probability greater than 90% in Egypt; and almost double that in India.

In the 3°C warming scenario, the probability of drought in Brazil and China is 30-40%; 20-23% in Ethiopia and Ghana; 14% in India but almost 100% in Egypt.

Finally in the 4°C warming scenario, the probability of drought in Brazil and China is close to 50%; 27-30% in Ethiopia and Ghana; almost 20% in India; and 100% in Egypt.

In most countries, the projected increase in the probability of drought increases approximately linearly with the increase in temperature. The exception is Egypt, where even a little global warming can lead to a large increased probability of drought.

Professor Rachel Warren, who led the overall study for which this paper is an output, said: “Not only does the area affected by drought increase as the earth warms, it also increases the length of droughts. .

“In Brazil, China, Ethiopia and Ghana, droughts lasting more than two years are forecast even in the 1.5°C warming scenario.”

In the 2°C warming scenario, the duration of drought is projected in all countries (except India) expected to exceed three years. In the 3°C warming scenario, drought is forecast to last about 4-5 years, and in the 4°C warming scenario, severe droughts lasting more than 5 years are forecast for Brazil and China, with severe drought being the new baseline condition.

In addition, the proportion of land that is projected to suffer a severe drought lasting more than 12 months over a 30-year period is expected to increase rapidly under the 1.5°C warming scenario in Brazil, China, and Brazil. countries and Egypt, and in areas with permanent snow. and ice in India.

Both India and China have large areas that are now ‘permanently’ covered by ice and snow. However, in a 3°C warming scenario, 90% of these regions are projected to face severe drought lasting more than one year over a 30-year period.

These areas are the headwaters of many major river systems, and thus provide water to millions of people downstream. The increased probability and duration of severe drought leads to a decrease in the potential to store water in the Chinese Himalayas in the form of snow and ice.

Drought can have major impacts on biodiversity, agricultural output and the economy. This study indicates that all six countries will need to deal with water stress in the agricultural sector, either through crop conversion or through irrigation, if water is available. Therefore, the level of adaptation required to cope with this increase in drought will increase rapidly with global warming.

The urban fare is only marginally better and generally shows the same pattern as above. Riverine or reservoir areas may have better prices, depending on competition for water and upstream water.

Professor Warren said: “Compliant with the Paris Agreement could have major benefits in terms of reducing the risk of severe drought in these six countries, in all major land cover types and for one billion large proportion of the world population.

“This requires urgent global action now to stop deforestation (including in the Amazon) this decade, and decarbonize the energy system this decade, so that we We can achieve net zero global greenhouse gas emissions by 2050.”

‘Quantifying meteorological drought risks between 1.5°C and 4°C of global warming in six countries’, published in The climate changes on September 28, 2022. DOI: 10.1007 / s10584-022-03359-2