Editorial: “Durban climate summit must accept degrees of responsibility“
It’s 2080. Global emissions peaked decades ago, too late to keep temperatures from rising more than 2 °C above preindustrial levels. The shift in climate has changed the world. As temperatures climbed by 2 °C, effects were felt first in poor and vulnerable regions like sub-Saharan Africa and south Asia. Extreme weather events – droughts, floods and hurricanes – became more common and severe. Vulnerable nations had a stark choice: adapt or face millions of deaths. At huge financial cost, society has adapted.
We cannot say for sure what kind of a home Earth will offer in 2080, but averages made across thousands of model runs help paint a picture of what a 2 °C warmer world would look like.
Read more: “Warmer world is the challenge of a generation“
One key difference will be the increase in extreme weather events. The good news is that with investment, we can adapt to some of this, says Saleemul Huq of the International Institute for Environment and Development. In 1991, a massive cyclone struck Bangladesh, killing 130,000 people. Afterwards, the country built shelters and early warning systems. When the equally powerful cyclone Sidr struck in 2007, the death toll was reduced to less than one-tenth of that. “Better preparation can bring down the casualty rates,” Huq says.
But above 2 °C, impacts are increasingly felt worldwide. The relative wealth of Europe and North America means they can build better defences and suffer far fewer deaths, but economic costs will be severe.
A warmer climate will be bad news for global agriculture, with regional winners and losers, says Andrew Challinor of the University of Leeds, UK. Agronomists are busy designing new varieties of staple crops like rice and wheat able to survive more frequent heatwaves and droughts, and organisations like the Consultative Group on International Agricultural Research are helping farmers find out what works for them. Despite such efforts, crops will fail more often (Environmental Research Letters, DOI: 10.1088/1748-9326/5/3/034012), probably leading to food-price spikes.
Cases of health problems ranging from heatstroke to infectious diseases will also increase. Models show tropical diseases will move into higher latitudes and altitudes with warming, though some believe that better public health in many affected regions will stave off the worst.
The degree of sea-level rise is a big uncertainty, but we know it lags behind temperature increases so the worst of those consequences probably will not have kicked in even by 2080. Scientists are also split on the link between temperature and human conflict. Some believe civil unrest will rise as the climate becomes harsher.
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