The evidence for climate change is irrefutable, it is impacting all areas of the globe and humans are the cause. While some of the effects of global warming are irreversible there is still time to prevent some of the worst impacts. However, the planet is warming faster than previously thought, and the window of opportunity to act is rapidly closing.
On August 9, 2021, the United Nations’ Intergovernmental Panel on Climate Change (IPCC) Working Group I released its sixth comprehensive assessment. This 3,500-page state-of-the-science report combines multiple lines of evidence making it the most comprehensive scientific undertaking on the climate crisis to date. This report was conducted by 751 scientists in more than 60 countries who reviewed more than 14,000 studies and data sources. Although the IPCC has released a number of smaller reports in recent years, this is the first major assessment in eight years. This report is intended for decision-makers and offers guidance to policymakers, governments, businesses, and individuals.
The report concludes that anthropogenic climate change is a “statement of fact”, and flatly refutes natural warming saying that humans are the “unequivocal” cause. Atmospheric emissions drive global warming and this, in turn, increases the frequency and severity of hurricanes, heatwaves, droughts, wildfires, sea-level rise, and flooding. Some of the current impacts are irreversible and some future impacts are inevitable. For example, we will not be able to stop the ice sheets from melting and this will cause sea levels to rise well beyond 2100 and stay higher for millennia. We can expect sea levels to rise up to five meters by 2150. Even if we keep temperatures below the 2 C upper threshold limit the seas will still rise by 2 to 3 meters.
The urgent need for immediate action
In the simplest possible terms, the latest IPCC report reinforces the case for urgent action to avoid catastrophic climate change. Time is of the essence, if we do not act soon we will exhaust our carbon budget. Humans have already emitted an estimated 2,390 Gigatons (Gt) of CO2 since 1850 which leaves us with only 300 gt in our carbon budget.
Present-day global concentrations of atmospheric carbon dioxide (CO2) are higher and rising faster than at any time in at least the past two million years. Since the middle of the last century, carbon dioxide and other greenhouse gases released as a result of human activities have trapped heat in the Earth’s atmosphere, raising the average temperature on land by approximately 1.09°C (1.96°F) above pre-Industrial norms. This is only 0.6 degrees away from the 1.5°C upper threshold limit (signatories of the Paris Accord agreed to an upper threshold limit of between 1.5°C and 2°C).
“Unless there are immediate, rapid, and large-scale reductions in greenhouse gas emissions, limiting warming to 1.5°C will be beyond reach,” said Ko Barrett, senior advisor for climate for NOAA’s Office of Atmospheric Research and one of three IPCC vice-chairs.
While it is still possible to keep temperatures below 1.5°C the chances are slim. According to the IPCC, the GHGs already in the atmosphere will likely push us past the 1.5°C threshold sometime between 2032 and 2050. Warming beyond this point risks triggering tipping points from which we may not be able to recover. However, the report was reassuring when it came to some of the most dangerous tipping points like the Arctic permafrost, which some scientists have said could release massive amounts of GHGs. The IPCC report concludes that the Arctic permafrost does not appear to be on the brink of collapse and its melting could be limited.
Other promising observations suggest that we are capable of drawing down emissions. Like many other crises, Covid-19 drove down emissions. The reductions in carbon emissions that we saw in 2020 shows that emissions reduction is possible. Under the IPCC’s most optimistic scenario (SSP1-1.9) global CO2 emissions will drop by roughly 25 percent by 2030 and about 50 percent by 2035.
We may not be able to prevent temperatures from temporarily surpassing 1,5°C but we may be able to avoid temperature increases that trigger tipping points. With consorted action, we can keep these temperatures from surpassing the 2-degree mark and we may be able to bring them back down below 1,5°C with carbon dioxide removal (CDR) from negative emission technologies (NETs) like direct air capture (DAC) and natural climate solutions (NCS). Failing to act will push us past the 2C threshold before 2050 and we will hit 3 or 4 degrees above the upper-temperature limit before the end of the century. If we slash emissions we can avert some of the worst impacts but we must act now.
Fossil fuels must end
Any serious effort to stop emitting GHGs (especially carbon dioxide and methane) entails eliminating fossil fuels which, according to the IPCC, are responsible for 85 percent of global warming. Curbing fossil fuels starts with an immediate end to new coal plants. In 2019, 36 billion tons of CO2 were released into the atmosphere and in 2020, 34 billion tons of atmospheric carbon came from fossil fuels. Increasing emissions from fossil fuels put us on a perilous trajectory. The IPCC found that the global average temperature increases are mainly due to the extensive use of fossil fuels. If they are not stopped they will destroy civilization as we know it.
IPCC scientist Gregory Flato, the Vice-Chair of IPCC’s Working Group I, told ZME, “the cause of that warming is human activity, mainly the burning of fossil fuels.” Chinese climate scientist Panmao Zhai said we can stop the negative climate trend by the middle of the century, by curbing the use of fossil fuels and stopping deforestation.
As explained by Leslie Hughes, professor of Biology at Macquarie University and councilor at the Climate Council, we must end fossil fuels :
“There must be no new oil, coal or gas exploration or infrastructure. We’ve got to stop subsidizing fossil fuels. We’ve got to electrify everything and then run everything from renewable energy…There must be no new coal plants built after 2021. OECD countries must phase out existing coal by 2030, with all others following suit by 2040.”
The IPCC report is clear, the worst impacts of climate change can still be averted if we stop burning fossil fuels. As explained by UN Secretary-General Antonio Guterres: “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,” he said adding this report “must sound a death knell” for fossil fuels.
Our actions will decide our future
Hughes succinctly explained where we are at when she said, what we do by 2030 will determine our future. In the 2015 Paris Climate Accord, almost every country on the planet committed to drawing down emissions to avoid exceeding the upper-temperature threshold limit, However, we are not doing anyway near enough to honor these pledges let alone improve upon them. Even if all the nations on the planet honored the commitments(INDCs) it would not be enough to keep temperatures within upper-temperature threshold limits.
We are careening towards increasing temperatures and extreme weather. This includes even stronger and more frequent storms, heatwaves, and wildfires, as well as longer and more intense droughts. Each fraction of a degree of additional warming translates to ever more devastating consequences. As Valérie Masson-Delmotte, co-chair of the IPCC report put it, “every additional tonne of CO2 emissions adds to global warming”.
The sixth assessment from Working Group I underscores the urgency of this year’s international climate summit in Glasgow. While this report focuses on the physical science of the climate system, other forthcoming reports will focus on impacts, adaptation, and vulnerability on humans and other species (Working Group II), and mitigation efforts (Working Group III).
Before these reports are released, global leaders will come together for COP26 in November, in what is widely seen as the most consequential climate policy meeting since the Paris Agreement was signed in 2015. “I hope today’s IPCC report will be a wake-up call for the world to take action now before we meet in Glasgow in November for the critical COP26 summit,” UK Prime Minister Boris Johnson said. The UN Secretary-General implored government leaders to ensure COP26 is a success in order to “avert climate catastrophe.”
The UN secretary-general described the latest IPCC report as signaling a “code red” adding “there is no time for delay and no room for excuses…The viability of our societies depends on leaders from government, business and civil society uniting behind policies, actions, and investments that will limit temperature rise to 1.5 degrees Celsius.” The IPCC makes it clear that the amount of climate change ahead depends on if and how quickly the world ramps down GHGs. What we do or don’t do to eliminate emissions will decide our fate.
If we were to substantially slash emissions in the next few years we could avoid the collapse of civilization. Flato optimistically believes that we can still avoid breaching the 1.5ºC temperature limit, but, he added we need to act now to institute transformative economy-wide changes. “The information we show is that rapid and drastic cut will allow us to stay below 1.5ºC but the longer we continue to emit the more warming that will happen. The only way to stop warming and stabilize temperature is to reach net-zero carbon emission. That is the goal to have in mind to stabilize temperature,” Flato said.
The key takeaway from the latest IPCC report is that we must act now and we must do more than we have heretofore agreed to do. As explained by Australian Green Leader Adam Bandt, “After this report, failure to lift 2030 targets is criminal negligence.”
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