You are here: Home » » Story

Global population exposed to water stress to be much lower at 1.5C warming level

New Delhi : The next few years are probably going to be the most important in our history. The message by the Intergovernmental Panel on Climate Change (IPCC) may be simple, but is ominous too.

In a recently released report to assess the differences between allowing temperatures to rise towards 2C above pre-industrial times or keeping them nearer to 1.5C, the IPCC has said that at 1.5C, the proportion of the global population exposed to water stress could be 50 per cent lower than at 2C.

Human activities are estimated to have caused approximately 1.0C of global warming above pre-industrial levels, with a likely range of 0.8C to 1.2C. Global warming is likely to reach 1.5C between 2030 and 2052 if it continues to increase at the current rate, the report noted.

"Depending on future socio-economic conditions, limiting global warming to 1.5C compared to 2C may reduce the proportion of the world population exposed to a climate change-induced increase in water stress by up to 50 per cent, although there is considerable variability between regions. Many small island developing states could experience lower water stress as a result of projected changes in aridity when global warming is limited to 1.5C, as compared to 2C", the report said.

Food scarcity would be less of a problem and hundreds of millions fewer people, particularly in poor countries, would be at risk of climate-related poverty, the special report on global warming of 1.5C' said.

Three working groups assessed different aspects of change: the physical scientific basis of climate change; impacts, adaptation and vulnerability; and climate change mitigation.

"The next few years are probably the most important in our history," Debra Roberts, co-chair of the IPCC Working Group that assessed impacts, adaptation and vulnerability, said.

According to the report, climate models project robust differences in regional climate characteristics between present-day and global warming of 1.5C, and between 1.5C and 2C. These differences include increases in: mean temperature in most land and ocean regions (high confidence), hot extremes in most inhabited regions (high confidence), heavy precipitation in several regions (medium confidence), and the probability of drought and precipitation deficits in some regions (medium confidence).

Risks from droughts and precipitation deficits are projected to be higher at 2C compared to 1.5C of global warming in some regions (medium confidence). Risks from heavy precipitation events are projected to be higher at 2C compared to 1.5C of global warming in several northern hemisphere high-latitude and/or high-elevation regions, eastern Asia and eastern North America (medium confidence), the report noted.

Populations at disproportionately higher risk of adverse consequences with global warming of 1.5C and beyond include disadvantaged and vulnerable populations, some indigenous peoples, and local communities dependent on agricultural or coastal livelihoods. Regions at disproportionately higher risk include Arctic ecosystems, dryland regions, small island developing states, and Least Developed Countries.

Poverty and disadvantage are expected to increase in some populations as global warming increases; limiting global warming to 1.5C, compared with 2C, could reduce the number of people both exposed to climate-related risks and susceptible to poverty by up to several hundred million by 2050.

Climate-related risks to health, livelihoods, food security, water supply, human security, and economic growth are projected to increase with global warming of 1.5C and increase further with 2C.

"Risks to global aggregated economic growth due to climate change impacts are projected to be lower at 1.5C than at 2C by the end of this century. This excludes the costs of mitigation, adaptation investments and the benefits of adaptation. Countries in the tropics and southern hemisphere subtropics are projected to experience the largest impacts on economic growth due to climate change should global warming increase from 1.5C to 2C", said the report.

The IPCC report stated that adaptation and mitigation are already occurring and future climate-related risks would be reduced by the upscaling and acceleration of far-reaching, multilevel and cross-sectoral climate mitigation and by both incremental and transformational adaptation.

Why forests should take centre stage during the water decade

Only a tiny fraction of national biodiversity plans consider the impact of forests on water supply, and only a fraction of national water plans place ecosystems at their centre.

more...