A new report on climate change issued by the United Nations is out and, if it's to be believed, that post-apocalyptic future suggested in such films as Mad Max: Fury Road and Snowpiercer may be here much sooner than we think.
Debra Roberts, co-chair of IPCC Working Group II (which assesses the impacts of climate change) saidthe 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 report also finds that, in the likelihood that governments fail to avert 2.7 degrees of warming, another scenario is possible: The world could overshoot that target, heat up by more than 3.6 degrees, and then through a combination of lowering emissions and deploying carbon capture technology, bring the temperature back down below the 2.7-degree threshold.
Sea level rises would be 10cm lower with a 1.5C temperature rise compared to 2C by the end of the century.
It also highlighted the environment has already seent he consequences of 1ºC of global warming in the form of more extreme weather, rising sea levels and diminishing Arctic Sea ice, among other changes. Coral reefs are projected to decline 70% to 90% at 1.5 degrees C, but at 2 degrees, 99% of reefs would be ravaged.
"Examples of actions include shifting to low- or zero-emission power generation, such as renewables; changing food systems, such as diet changes away from land-intensive animal products; electrifying transport and developing "green infrastructure", such as building green roofs, or improving energy efficiency by smart urban planning, which will change the layout of many cities", the report said.
"E$3 ven with erroneous attribution of extreme weather/climate events and projections using climate models that are running too hot and not fit for objective of projecting 21st century climate change, the IPCC still has not made a strong case for this massive investment to prevent 1.5C warming", she said on her Climate Etc. blog.
"For some people this is a life-or-death situation without a doubt", said Cornell University climate scientist Natalie Mahowald, a lead author on the report.
Allowing the global temperature to temporarily exceed or "overshoot" 1.5ºC would mean a greater reliance on techniques that remove Carbon dioxide from the air to return global temperature to below 1.5°C by 2100.
A major report prepared by the United Nations body for climate change, the Intergovernmental Panel on Climate Change, has called for "rapid, far-reaching and unprecedented changes in all aspects of society". "Every bit of extra warming makes a difference", said Abdalah Mokssit, director of Morocco's National Meteorological Department and IPCC secretary.
The US, along with 180 other countries, accepted the report's summary line by line.
As the IPCC's reports are largely based on a critical assessment and synthesis of published scientific papers, many of its latest conclusions are unsurprising. Current annual emissions are about 42 billion tonnes, implying about a decade of pollution before "the need to go vertical" to zero emissions to keep within the temperature limit. Pathways reflecting these ambitions would not limit global warming to 1.5°C, even if supplemented by very challenging increases in the scale and ambition of emissions reductions after 2030 (high confidence). Starting in 1994, a central aim of the UN's climate change efforts (the Framework Convention on Climate Change, or UNFCCC) was to stabilise greenhouse gas concentrations at a level that would "prevent risky anthropogenic interference with the climate system". The planet is already two-thirds of the way there, with global temperatures having warmed about 1°C above pre-industrial levels.
That 1.5 degrees C target is also an entirely fabricated artefact.
Scientists with the Nobel Prize-winning IPCC said in order to have even a 50-50 chance of staying under the 1.5 degree cap, the world must become "carbon neutral" by 2050.
Despite the controversial policy implications, the U.S. delegation joined more than 180 countries on Saturday in accepting the report'ssummary for policymakers, while walking a delicate diplomatic line.
Within these scenarios, by 2030 coal use would need to drop between 25 percent and 60 percent compared to 2010.
Warrick said her organisation intends to campaign for governments to invest in carbon capture technology. "But it will require unprecedented and collective climate action in all areas".