We have 12 years to save the planet, calculate scientists in the starkest warning yet that our chances of tackling climate change and averting disaster are slipping away. After 2030, its future is a gamble, relying on untested technologies and techniques, and the environmental outlook is unreliable, and bleaker than ever. This is the conclusion of a landmark state-of-the-planet report by the United Nations (UN) Intergovernmental Panel on Climate Change (IPCC), released on Monday.
“The next few years are probably the most important in our history,” said the UN. Limiting global warming will require “rapid, far-reaching, and unprecedented” changes in all aspects of society, the UN said.
Societal change, enabled by technological advancement, cannot come soon enough. Governments, enterprises, and individuals must change urgently and commit totally if environmental catastrophe is to be averted, said the UN. More “rapid and far-reaching” transitions in energy, industry, buildings, transport, and cities are required if global warming is to be limited to 1.5°C, calculated as the maximum rise to retain environmental stability.
The report says human-caused emissions of carbon dioxide (CO2) would need to fall by 45 per cent from 2010 levels by 2030, reaching ‘net zero’ around 2050, if the 1.5°C target is to be kept in sight. But current efforts to achieve environmental sustainability are not enough to make the 2030 deadline, the UN said.
“Limiting warming to 1.5°C is possible within the laws of chemistry and physics but doing so would require unprecedented changes,” said Jim Skea, co-chair of the IPCC’s working group III, one of three IPCC working groups, covering the evidence, impacts, and solutions around climate change, respectively.
Allowing the temperature to exceed 1.5°C would mean a greater reliance on techniques that remove CO2 from the air to return global temperature to below 1.5°C by 2100. These techniques are unproven at large scale and some carry significant risks for sustainable development, the report notes.
“Limiting global warming to 1.5°C compared with 2°C would reduce challenging impacts on ecosystems, human health and well-being, making it easier to achieve the United Nations Sustainable Development Goals,” commented Priyardarshi Shukla, also co-chair of the IPCC’s working group III.
The stakes could not be higher. By 2100, global sea level rise would be 10 cm lower with global warming of 1.5°C compared with 2°C. The likelihood of an Arctic Ocean free of sea ice in summer would be once per century with global warming of 1.5°C, compared with at least once per decade with 2°C.
Coral reefs would decline by 70-90 per cent with global warming of 1.5°C, whereas virtually all would be lost with 2°C.
Limiting global warming would give people and ecosystems more room to adapt and remain below relevant risk thresholds, said Hans-Otto Pörtner, co-chair of the IPCC’s working group II. “Every extra bit of warming matters, especially since warming of 1.5°C or higher increases the risk associated with long-lasting or irreversible changes, such as the loss of some ecosystems.”
The report reviews four pathways to limit warming to 1.5°C. “The good news is that some of the kinds of actions that would be needed to limit global warming to 1.5°C are already underway around the world, but they would need to accelerate,” said Valerie Masson-Delmotte, co-chair of the IPCC’s working group I.
Debra Roberts, co-chair of the IPCC’s working group II, explained: “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.”
The UN IPCC report will be a key scientific input into the Katowice Climate Change Conference in Poland in December, when governments review the Paris Agreement to tackle climate change.
Ninety-one authors and review editors from 40 countries prepared the IPCC report in response to an invitation from the UN Framework Convention on Climate Change (UNFCCC) when it adopted the Paris Agreement in 2015. They have considered 6,000 pieces of evidence.
“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,” said Panmao Zhai, co-chair at the IPCC’s working group I.
The Paris Agreement adopted by 195 nations in December 2015 included the aim of strengthening the global response to the threat of climate change by “holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels.”
As part of the Paris Agreement, the IPCC was invited to produce its ‘special report’ on global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways.
