‘Unprecedented Changes.’ New UN Report Says Saving the World From Climate Change Will Be a Lot Harder Than We Thought

The United Nations body on Monday presented a special report on global warming that was requested under the 2015 Paris Agreement. The report is comprehensive, citing over 6,000 scientific references, and its basic message is this: limiting warming to a rise of 1.5 degrees compared with pre-industrial levels will require an unprecedented amount of effort, but a rise of 2 degrees would be far more harmful and ultimately more costly, too.

So far, temperatures have increased around 1% since the second half of the 19th century. This rise is already causing rising sea levels and more extreme weather, and the figure is going up by around 0.2 degrees per decade.

“This report gives policymakers and practitioners the information they need to make decisions that tackle climate change while considering local context and people’s needs. The next few years are probably the most important in our history,” said Debra Roberts, co-chair of the IPCC division that deals with the impacts of climate change and the adaptations needed to respond to it.

According to the report, limiting warming to a 2-degree rise would require CO2 emissions to drop by around 20% from 2010 levels by 2030, reaching “net zero” (through the use of carbon-capturing technologies) by 2075. Achieving only a 1.5-degree rise means cutting emissions by 45% by 2030, and reaching net zero around 2050.

What’s the difference? 2 degrees means no more coral reefs, while 1.5 degrees mean only most will be wiped out. The higher figure also means hundreds of millions more people experiencing severe heatwaves and risking starvation due to lower crop yields.

So what should governments be doing? The report sets out a few suggestions:

• Energy: Coal needs to be phased out and cleaner energy sources expanded, probably including nuclear power and fossil-fuel power that comes with carbon dioxide capture and storage.
• Land: Vast amounts of pasture and non-pasture agricultural land needs to be converted to the production of energy crops. The report notes that “mitigation options limiting the demand for land include sustainable intensification of land use practices, ecosystem restoration and changes towards less resource-intensive diets.”
• Urban and infrastructure: Land and urban planning practices need to change. Buildings and transportations systems need to use less energy.
• Industrial systems: More technological innovation is needed, to help mitigate warming and to help people adapt.

The IPCC noted in its report that the transitions needed are “unprecedented in terms of scale, but not necessarily in terms of speed, and imply deep emissions reductions in all sectors, a wide portfolio of mitigation options and a significant upscaling of investments in those options.”

“Limiting warming to 1.5 degrees Celsius is possible within the laws of chemistry and physics but doing so would require unprecedented changes,” said Jim Skea, who co-chairs the IPCC group that studies the mitigation of climate change.

Models of scenarios where warming is limited to 1.5 degrees all involve mass deployments of carbon dioxide removal techniques and technologies, such as reforestation and carbon capture and storage, although the extent of those deployments really depends on how much we start cutting CO2 emissions before 2030.

The Paris Agreement, from which the U.S. has effectively withdrawn under the Trump presidency, commits countries to “holding the increase in the global average temperature to well below 2 degrees Celsius above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5 degrees Celsius above pre-industrial levels.”

It’s not just the U.S. that isn’t playing ball here. The new Australian prime minister, Scott Morrison, said Monday that he would not withdraw the country from the Paris Agreement, but his government also wouldn’t stick to electricity-sector targets that involve the phasing-out of coal.

“We’re not held to any of [the targets] at all,” Morrison said. “Nor are we bound to go and tip money into that big climate fund. We’re not going to do that either. I’m not going to spend money on global climate conferences and all that nonsense.”

As for what ordinary people can do to help save the world from overheating, check out these tips that were released by thousands of scientists late last year.