On Monday, the Intergovernmental Panel on Climate Change (IPCC) released its sixth assessment report, addressing the most up-to-date physical understanding of the climate system, bringing together climate scientists from across the globe and the latest advances in climate science to warn of the imminent and dire risk of climate change. 

This Report responds to the invitation for IPCC ‘… to provide a Special Report in 2018 on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways’ contained in the Decision of the 21st Conference of Parties of the United Nations Framework Convention on Climate Change to adopt the Paris Agreement. This Summary for Policymakers (SPM) presents the key findings of the Special Report, based on the assessment of the available scientific, technical and socio-economic literature relevant to global warming of 1.5°C and for the comparison between global warming of 1.5°C and 2°C above pre-industrial levels. 

The Report, produced by hundreds of the world’s top scientists and signed off by all the world’s governments, concludes that it could get far worse if the slim chance remaining to avert heating above 1.5°C is not immediately grasped. The scientific language of the report is cold and clear, it cannot mask the heat and chaos that global warming is unleashing on the world. We have already caused 1°C of heating, getting perilously close to the 1.5°C danger limit agreed in the Paris climate deal. The Report is clear there are no cliff-edges to the climate crisis. Each tonne of carbon pumped out increases the impacts and risks of extreme heat, floods and droughts and so every tonne of carbon matters. It will never be too late to act, the report shows. Instead, the real question is how bad will it get and what can we do next?

The authors conclude that it is “unequivocal” that humans have warmed the planet, causing “widespread and rapid” changes to Earth’s oceans, ice and land surface. They warn that the present state of many parts of the climate system is “unprecedented over many centuries to many thousands of years”.

Many of these changes – particularly to the oceans, ice sheets and global sea levels – are “irreversible”, the authors say. Abrupt changes and “tipping points” – such as rapid Antarctic ice sheet melt and forest dieback – “cannot be ruled out”. One of the key developments since the IPCC’s last assessment report in 2013-14 is the strengthening of the links between human-caused warming and increasingly severe extreme weather, the authors say. This is now “an established fact”, they write.

Pending request – Doomsday

Many news headlines have immediately struck for the doomsday narrative. We cannot avert the catastrophes that can already be seen across the globe – from wildfires spreading across the Mediterranean, the shifts in the Gulf stream changing significant weather patterns, warming temperatures across the globe…the list goes on. “We’re already experiencing climate change, including more frequent and more extreme weather events,” IPCC author Prof Ed Hawkins of the University of Reading told a press briefing, adding that “the consequences will continue to get worse for every bit of warming, and for many of these consequences, there’s no going back”.

In almost all emissions scenarios, global warming is expected to hit 1.5C “in the early 2030s”, the Report says. And without reaching “net-zero” CO2 emissions – along with “strong reductions” in other greenhouse gases – the climate system will continue to warm. 

The Report highlighted countries destined for extreme weather events and increased vulnerability, and how they are at risk of high deaths and possible ‘extinction’, a message mirrored across the media. This is a seemingly final blasting of the trumpet, albeit one very late to the chorus of activists, NGOs and environmental organisations that have been calling out for far longer. We need to take action sooner rather than later to protect those at risk. 

“We are paying with our lives for the carbon someone else emitted,”

Mohamed Nasheed, a former Maldives president who represents almost 50 countries that are vulnerable to the effects of climate change. 

Responsibility for addressing climate change is not equally distributed. According to a report by the Carbon Disclosure Project, only 100 companies are responsible for 71% of total greenhouse gas emissions since 1998. High-income countries have historically emitted a disproportionate amount of pollution. Despite years of climate action the US and EU are responsible for 23% of emissions, representing only 10% of the world population.

“We need justice. We need action.” Greta Thunberg voiced the opinions of multitudes of activists, scientists, environmentalists and more as she tweeted her opinion on the IPCC report and its global reaction. “The new IPCC report contains no real surprises. It confirms what we already know from thousands of previous studies and reports – that we are in an emergency. It’s a solid (but cautious) summary of the current best available science.“

Although the IPCC has been warning about the perils of global warming for three decades, governments have yet to take the kind of action necessary to transition to clean-energy sources and halt greenhouse-gas emissions. But perhaps things are about to change, argues Nature, if only because people all over the world are starting to see the impacts of climate change around them. 

Unveiling the report, UN environment programme chief Inger Ansersen said: “Nobody’s safe and it’s getting worse faster. We must treat climate change as an immediate threat.”

This is the first time the influential group of scientists could state that climate change is already impacting every inhabited region on the planet – thanks to advances in attribution science, which assesses human influence on weather. 

Visualization of the increase in global average temperature between 1850-2020.  Credit: ShowYourStripes

Earlier in the year, the UK Met Office and World Meteorological Organization released research demonstrating that there is more than a 40% chance that the annual average global temperature in at least one of the next five years will temporarily reach 1.5C above pre-industrial levels. Through the Paris Agreement in 2015, the international community agreed to keep global temperature rise this century well below 2.0°C degrees above pre-industrial levels, and to pursue efforts to limit temperature increase to 1.5°C. The 1.5°C threshold is important because beyond this, so-called “tipping points” – positive feedback loops where global warming causes a permanent shift in earth systems, locking in further warming – become more likely. 

The IPCC climate change report brings forward the timeline for when scientists expect it to reach 1.5C to the mid-2030s, at which point tipping points such as loss of arctic sea ice, larger-scale die-offs of coral reefs, and thawing of the methane-rich permafrost become much more likely. The Environmental Change Institute at Oxford shows a constantly updated assessment of human-induced global warming, showing the precarious situation described by the IPCC in stark numbers.

“Many changes due to past and future greenhouse gas emissions are irreversible for centuries to millennia.”

the World Meteorological Organisation reported, a clarion call for urgent action.

The science tells us that to limit the worst consequences of climate change, we must aim for net zero as soon as possible, and by 2050 at the very latest, and that we need rapid short-term decarbonization efforts this decade. The science is pushing for politicians, governments, international businesses and individuals to collaborate together to prevent the mass deterioration of our planet.

UN secretary-general Antonio Guterres said the report was a “code red for humanity”.

He warned:

“The alarm bells are deafening, and the evidence is irrefutable: greenhouse gas emissions from fossil fuel burning and deforestation are choking our planet and putting billions of people at immediate risk.”

Moreover, there is an increasing moral and economic imperative to respond to the consequences of climate change we are already witnessing. The poorest communities are often those that contribute the least to climate change but are most vulnerable to its consequences. Through the UN Framework Convention on Climate Change’s (UNFCCC) Conference of Parties (COP) process, these countries are able to leverage their equal status to their richer counterparts as UNFCCC parties to highlight the importance of climate adaptation and resilience. 

Following through to COP26…

The overarching goal of COP26 President Alok Sharma is for the international community to come forward in Glasgow in November with long-term emission reductions targets, complemented by immediate short-term action to ‘keep 1.5 alive’. As we have learned from the COVID-19 pandemic, prevention is better, and far less costly, than cure.

The COP26 Summit will be unprecedented in bringing business leaders into the global effort on climate change, and public-private collaboration will be key to achieving these dual goals of mitigating carbon emissions to keep 1.5C alive, and supporting all communities to adapt to, and be resilient to, climate change.

The IPCC process will continue. Researchers will submit papers for peer review and publication in scientific journals, and the IPCC’s lead authors will pick the most significant for further investigation and inclusion in a seventh assessment report, likely to be published towards the end of this decade.

There will be one stark difference between this report and the next, however: this is the last IPCC report to be published where we still have a chance of averting the worst crises of climate breakdown…

Image credit: IPCC