Experts across the globe have put their collective heads together to deliver a landmark report on the potentially devastating impact of climate change – and their conclusions are not good news.
The Intergovernmental Panel on Climate Change (IPCC) has effectively delivered a final call on world leaders to take urgent action to stop the planet from overheating.
Urgency around the subject is being increasingly recognised, and it was announced on Monday that the Nobel Prize for Economics was awarded to William Norhaus and Paul Romer for work on climate change and innovation.
The coalition of IPCC scientists and policy experts predict the average global temperature will hit the crucial threshold of 1.5C above pre-industrial levels by 2030.
Countries around the world must now act to completely cut out global carbon emissions by 2050, the UN-backed research says, or risk mass food shortages, more floods, droughts, storms.
Greenpeace’s Kaisa Kosonen summed up why the report matters: “Scientists might want to write in capital letters, ‘ACT NOW IDIOTS’, but they need to say that with facts and numbers. And they have.”
Here’s everything you need to know.
Where Has The Warning Come From?
The Special Report on Global Warming 1.5C, known as SR15, was produced by the Intergovernmental Panel in Climate Change report, a UN consortium of researchers studying the speed and scope of temperature rise caused by humans.
Is It A Big Deal?
Very – the report calls for “rapid, far-reaching and unprecedented changes in all aspects of society”.
Ninety-one authors and review editors from 40 countries prepared the IPCC report, which contains 6,000 scientific references.
It furthers the Paris Agreement of 2015, where and aim of limiting global temperature rises to “well below” 2C was set.
Panmao Zhai, co-chair of the IPCC Working Group I (which assesses the science of climate change), said: “One of the key messages that comes out very strongly from this report is that we are already seeing the consequences of 1°C of global warming through more extreme weather, rising sea levels and diminishing Arctic sea ice, among other changes.”
Debra Roberts, co-chair of IPCC Working Group II (which assesses the impacts of climate change) said the 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,” she added.
How Can Cuts Be Achieved?
Carbon emissions need to reach “net zero” by 2050 and nearly halve from 2010 levels by 2030.
This means no more CO2 should be put out than is being removed by current measures, such as planting trees.
The targets rely on increased use of renewable energy, to the point that they product 70 to 85% of electricity supplies by 2050.
Coal power would also need to be reduced to almost nothing.
Emissions cuts in transport, buildings, industry, power generation and dietary habits such as eating meat will need to take place in a bid to speed up temperature limits.
How Much Global Warming Has There Been Already?
Currently, the world has seen 1C of warming over the past 115 years, according to a US report last year.
The rise has already triggered consequences we are seeing through the seasons such as more extreme weather. Global sea levels rose 17cm in the 20th century.
Global temperature is currently rising 0.2C with each decade, and it is estimated we will reach 1.5C by 2040.
What Will We See Once Global Warming Is Limited To 1.5C?
It is thought that by 2100, global sea rise levels would be 10cm lower that if global warming were to be at 2C. Coral reefs, which risk decline by more than 99% at 2C, would reduce by 70 to 90%.
Small islands and coastal cities such as New York and Mumbai risk going underwater without the installation of sea barriers.
The review of thousands of scientific papers also said the spread of disease and economic damage and harm to yields of crops will be less severe at 1.5C than 2C, as will the extinction of species.
Health benefits will also be experienced as we will see lower levels of air pollution and the alleviation of poverty in the developing world.
In the US – one of the world’s biggest emitters – policies under the Trump administration are rolling back efforts to reduce carbon footprints, including pulling out of the Paris Agreement last year.
What Has Been The Reaction So Far?
Experts have said “unprecedented” should take place and said the report should urge governments to invest in clean growth and renewable energy.
Professor Jim Skea, from Imperial College London and one of the report researchers, said: “The changes that would be needed to keep global warming to 1.5C are really unprecedented in terms of their scale. We can’t find any historical analogies for it.
“There are some areas we are making progress quickly enough that they are compatible with 1.5C, the example of renewables is one, where we’ve seen costs falling and deployment across the world.
“We need to extend this kind of progress on renewables to other areas.”
Professor Corinne Le Quere, from the University of East Anglia, said: “For the UK, this means a rapid switch to renewable energy and electric cars, insulating our homes, planting trees, where possible walking or cycling and eating well – more plants and less meat – and developing an industry to capture carbon and store it underground.
“It also means adapting to the growing impacts of climate change that are felt here, particularly to the increasing flood risks from heavy rainfall and from sea level rise along our coasts.”
The UK already has a target to cut greenhouse gas emissions by 80% by 2050.