Climate change impact worse than feared: Report

Incheon, South Korea: A landmark report from the United Nations’ scientific panel on climate change paints a far more dire picture of the immediate consequences of climate change than previously thought and says that avoiding the damage requires transforming the world economy at a speed and scale that has “no documented historic precedent.”

The report, issued on Monday by the Intergovernmental Panel on Climate Change, a group of scientists convened by the United Nations to guide world leaders, describes a world of worsening food shortages and wildfires, and a mass die-off of coral reefs as soon as 2040 — a period well within the lifetime of much of the global population.

The report “is quite a shock, and quite concerning,” said Bill Hare, an author of previous IPCC reports and a physicist with Climate Analytics, a nonprofit organisation. “We were not aware of this just a few years ago.” The report was the first to be commissioned by world leaders under the Paris agreement, the 2015 pact by nations to fight global warming.

What is the one big takeaway?

The authors found that if greenhouse gas emissions continue at the current rate, the atmosphere will warm up by as much as 2.7 degrees Fahrenheit (1.5 degrees Celsius) above preindustrial levels by 2040, inundating coastlines and intensifying droughts and poverty.

Previous work had focused on estimating the damage if average temperatures were to rise by a larger number, 3.6 degrees Fahrenheit (2 degrees Celsius), because that was the threshold scientists previously considered for the most severe effects of climate change. The new report, however, shows that many of those effects will come much sooner, at the 2.7-degree mark.

What does the world need to do?

Avoiding the most serious damage requires transforming the world economy within just a few years, said the authors, who estimate that the damage would come at a cost of $54 trillion (Dh198.2 trillion). But while they conclude that it is technically possible to achieve the rapid changes required to avoid 2.7 degrees of warming, they concede that it may be politically unlikely.

For instance, the report says that heavy taxes or prices on carbon dioxide emissions — perhaps as high as $27,000 per tonne by 2100 — would be required. But such a move would be almost politically impossible in the United States, the world’s largest economy and second-largest greenhouse gas emitter behind China. Lawmakers around the world, including in China, the European Union and California, have enacted carbon pricing programmes.

How much will tackling climate change cost?

It won’t come cheap. The report says that to limit warming to 1.5C, it will involve “annual average investment needs in the energy system of around $2.4 trillion” between 2016 and 2035. But experts believe that this number needs to be put in context. “There are costs and benefits you have to weigh up,” Dr Stephen Cornelius, a former UK IPCC negotiator now with WWF, told the BBC. He said that cutting emissions hard in the short term will cost money, but is cheaper than paying for carbon dioxide removal later this century.

Who all compiled the report?

The report was written and edited by 91 scientists from 40 countries who analysed more than 6,000 scientific studies. The Paris agreement set out to prevent warming of more than 3.6 degrees Fahrenheit above preindustrial levels — long considered a threshold for the most severe social and economic damage from climate change. But the heads of small island nations, fearful of rising sea levels, had also asked scientists to examine the effects of 2.7 degrees of warming.

Are all world leaders on the same page?

Not really. US President Donald Trump, who has mocked the science of human-caused climate change, has vowed to increase the burning of coal and said he intends to withdraw from the Paris agreement. And on Sunday in Brazil, the world’s seventh-largest emitter of greenhouse gas, voters appeared on track to elect a new president, Jair Bolsonaro, who has said he also plans to withdraw from the accord.

The World Coal Association disputed the conclusion that stopping global warming calls for an end of coal use. In a statement, Katie Warrick, its interim chief executive, noted that forecasts from the International Energy Agency, a global analysis organisation, “continue to see a role for coal for the foreseeable future.”

Intergovernmental Panel on Climate Change chair Hoesung Lee (left) unveils the report in Incheon. AP

What will happen if no one takes urgent action?

Absent aggressive action, many effects once expected only several decades in the future will arrive by 2040, and at the lower temperature, the report shows. “It’s telling us we need to reverse emissions trends and turn the world economy on a dime,” said Myles Allen, an Oxford University climate scientist and an author of the report.

Global sea-level will rise around 10 centimetres more if we let warming go to 2Celsius. That may not sound like much but keeping to 1.5C means that 10 million fewer people would be exposed to the risks of flooding. There are also significant impacts on ocean temperatures and acidity, and the ability to grow crops like rice, maize and wheat.

So what needs to be done now by countries around the world?

To prevent 2.7 degrees of warming, the report said, greenhouse pollution must be reduced by 45 per cent from 2010 levels by 2030, and 100 per cent by 2050. It also found that, by 2050, use of coal as an electricity source would have to drop from nearly 40 per cent today to between 1 and 7 per cent.

Renewable energy such as wind and solar, which make up about 20 per cent of the electricity mix today, would have to increase to as much as 67 per cent. “This report makes it clear: There is no way to mitigate climate change without getting rid of coal,” said Drew Shindell, a climate scientist at Duke University and an author of the report.