It doesn’t have to be like this.
The world already has the know-how and tools to drastically reduce emissions from fossil fuels — but we must use those tools immediately if we hope to prevent the worst effects of climate change. That is the message of the third and final installment of the United Nations Intergovernmental Panel on Climate Change’s massive sixth assessment of climate science, released April 4.
“We know what to do, we know how to do it and now it’s up to us to take action,” said Jim Skea, sustainable energy researcher at Imperial College London, who co-led the report a news event announcing its release.
The Earth is on track to warm by an average of about 3.2 degrees Celsius above pre-industrial levels by the end of the century (SN: 11/26/19). Changing that course and limiting warming to 1.5 degrees or even 2 degrees means that global emissions from fossil fuels must peak by 2025 at the latest, the new report says.
At the moment it seems extremely unlikely that this will be achieved. National pledges to date to reduce fossil fuel emissions are “a litany of broken climate pledges,” United Nations Secretary-General António Guterres said at the event.
The previous two parts of the IPCC’s sixth assessment described how climate change is already fueling extreme weather events around the world – and found that adaptation alone will not be enough to protect people from these threats (SN: 8/9/21; SN: 02/28/22).
The looming climate crisis “is appalling, and I don’t want to sugarcoat it,” says Bronson Griscom, forest ecologist and director of Natural Climate Solutions at environmental organization Conservation International, based in Arlington, Virginia.
But Griscom, who was not an author of the new IPCC report, says its findings also give him hope. It’s “what I would call a double-or-nothing bet that we’re facing right now,” he says. “There [are] In a number of ways this report is basically saying, “Look, if we don’t do anything, it’s going to get darker and darker.” But the reasons for doing something are incredibly powerful and the tools in the toolbox are very powerful.”
Tools in the tool box
These tools are strategies that governments, industries, and individuals can use to immediately reduce emissions across multiple sectors of the global economy, including transportation, energy, construction, agriculture, forestry, and urban development. Immediately capitalizing on opportunities to reduce emissions in each of these sectors would halve global emissions by 2030, the report said.
Consider the transport sector, which accounted for 15 percent of man-made greenhouse gas emissions in 2019. Worldwide, electric vehicle sales have risen sharply in recent years, mainly due to government policies and stricter emission laws for the auto industry (SN: 12/22/21).
If this increase continues, “electric vehicles offer us the greatest potential [to reduce transportation emissions on land], as long as they are combined with low-carbon or zero-carbon power sources,” said Inger Andersen, executive director of the United Nations Environment Programme, at the news event. But for aviation and long-distance shipping, which are more difficult to electrify, lower CO2 emissions could be achieved with low-carbon hydrogen fuels or biofuels, although these alternatives require further research and development.
Then there are urban areas, which account for a growing share of global greenhouse gas emissions, from 62 percent in 2015 to between 67 and 72 percent in 2020, the report notes. In established cities, buildings can be retrofitted, renovated or repurposed to make city layouts more walkable and provide more accessible public transportation.
And growing cities can integrate energy-efficient infrastructure and construct buildings with zero-emission materials. In addition, urban planners can use green roofs, urban forests, rivers and lakes to capture and store carbon, as well as provide other climate benefits such as cleaner air and local cooling to counteract urban heatwaves (SN: 4/3/18).
Meanwhile, “reducing emissions in industry includes using materials and energy more efficiently, reusing and recycling products, and minimizing waste,” Diana Ürge-Vorsatz, vice chair of IPCC Working Group III, said at the press conference .
As for agriculture and forestry, these and other land-use industries contribute about 22 percent of global greenhouse gas emissions, with half of those emissions coming from deforestation (SN: 07/13/21). So reforestation and reduced deforestation are key to reversing the balance between CO₂ emissions and removal from the atmosphere (SN: 7/9/21; SN: 1/3/22). But there are many other strategies the world can employ at the same time, the report points out. Better management of forests, coastal wetlands, grasslands and other ecosystems, more sustainable management of crops and livestock, soil carbon management in agriculture and agroforestry can all reduce emissions (SN: 07/14/21).
The report also includes, for the first time in the IPCC reports, a chapter on the “untapped potential” of lifestyle changes to reduce emissions. These changes include choosing to walk, bike or use public transport instead of driving, switching to a plant-based diet and reducing air travel (SN: 05/14/20).
These lifestyle changes could reduce emissions by 40 to 70 percent by 2050, the report says. However, to enable these changes, government policies, infrastructure and technology would need to be in place.
Government policy is also key to funding these transformative changes. Global investment in climate-related technologies must ramp up, and fast, to limit warming to below 2 degrees C, the report says. Investments are currently three to six times lower than they need to be by 2030. And a combination of public and private investment will be essential to support the transition from fossil fuels to renewable energy in developing countries (SN: 01/25/21).
Still, reducing emissions alone will not be enough: we must actively remove carbon from the atmosphere to achieve net-zero emissions and keep the planet well below 2 degrees warming, the report says. “One thing that is clear in this report, unlike previous reports, is that carbon removal will be necessary in the near future,” said Simon Nicholson, director of the Institute for Carbon Removal Law and Policy at American University in Washington . DC, who was not involved in the report.
Such strategies include existing approaches such as protecting or restoring carbon-absorbing forests, but also technologies that are not yet widely commercially available, such as capturing carbon dioxide directly from the air or converting the gas into a mineral form and underground storage (SN: 12/17/18).
Those options are in their infancy, and we don’t yet know how much impact they will have, says Nicholson. “We now need massive investments in research.”
The emphasis on acting now, eliminating further delays and the urgency of the moment was a recurring theme in all three sections of the IPCC’s Sixth Assessment Report, released last year. It is unclear what impact the blatant statements made by these scientists will have.
But “the jury has reached a verdict, and it is devastating,” said UN Secretary-General Guterres. “If you care about justice and the future of our children, I speak to you directly.”