Climate, if we don't save the planet now we will never do it again

Climate, if we don't save the planet now we will never do it again


On March 20, the United Nations' Intergovernmental Panel on Climate Change (IPCC) released what could become a landmark document on human progress (or lack thereof, if we don't heed its warnings). This is a "synthesis" report that summarizes the findings of six previous IPCC reports, which explained the science behind climate change, the ways in which the food system emits greenhouse gases and how the oceans are transforming and the polar regions. The report is a heartfelt plea for our species to make the huge – but doable – changes needed to limit the damage caused by every fraction of a degree of warming. The latest IPCC document also represents a sort of goodbye, since the group's next climate report will not arrive for at least another five years.

" To ensure a livable and sustainable future for all c "It is a window of opportunity that is rapidly closing – reads the report –. The choices and actions taken in this decade will have an impact on the present and for thousands of years".

Clear warning

The more warming increases, the more difficult it will be to take mitigation actions to protect human health, agriculture and the natural world. Some effects, such as the collapse of ecosystems, will be irreversible. "The synthesis report underscores the importance of not only accelerating climate action, but doing it in a way that helps everyone in the world, not just people in the wealthiest countries and regions," co-author said in a statement. of the report Christopher Trisos, director of the Climate risk lab at the African climate and development initiative.

The science of climate change is 'unambiguous,' the report points out: We've already warmed the planet by 1.1 degrees Celsius above pre-industrial levels, triggering wildfires, heat waves, droughts and more violent storms, which they are killing humans and destabilizing ecosystems. However, how much the planet will continue to warm up, and at what speed, depends on a series of unknown factors, for example future economic development and still little-known phenomena such as the 2 thawing of the permafrost and the consequent release of carbon dioxide (CO 2 ) . Furthermore, scientists have not yet gained a precise idea of ​​the global influence exerted by the aerosols produced by the combustion of fossil fuels, which tend to cool the atmosphere: decarbonising the planet (an objective that we must certainly pursue), we could lose part of this beneficial effect .

In any case, it is increasingly evident that we will not be able to meet the goal of limiting global warming to 1.5 degrees, as set out in the Paris agreements . In fact, to avoid this rise in temperatures we should cut our emissions in half by 2030. " Even the most optimistic of scientists think that we have now missed that train - explains Claudia Tebaldi, climatologist at the Pacific Northwest National Laboratory and lead author of a previous report from the 'IPCC, which however was not involved in the new synthesis – We may be able to get back to 1.5 degrees, but we would need a miracle to stay below 1.5".

Opportunities and challenges

Techniques to remove carbon dioxide, for example by aspirating it from the atmosphere, could reduce warming. While the new report stresses that they will be needed to bring temperatures down, at present, however, these technologies have not yet been tested on a scale close to that needed to make a significant impact.

Today, the collapse in the prices of renewable energy is driving decarbonisation: wind energy prices have fallen by 55 percent in the 1910s, according to the new report, while solar energy and lithium-ion batteries have become 85 percent cheaper , much less than the researchers had anticipated. However, lower prices have allowed solar panels to proliferate, reducing reliance on fossil fuels, with scientists scrambling to find new places to install them, from parking lots to garden rooftops, farmlands to canals, and reservoirs. water .

The report "clarifies that the world has made some progress on the front of climate change; the good news is there – declares Zeke Hausfather, a researcher for Stripe and the non-profit association Berkeley earth -. At At the same time, there is a large gap between where we are now – and where countries are committed to achieving by 2030 – and what is needed to meet our more ambitious climate goals.”

The future remains uncertain. When building their models of climate change, scientists imagine different scenarios in which humanity reduces emissions, keeps them constant or increases them. These models produce a series of figures relating to the potential warming of the planet. Not long ago, experts estimated that, based on the trend in emissions, an increase of 4 or 5 degrees could not be ruled out. But last year Hausfather and his colleagues found that if countries stick to their pledges, we may be able to keep warming below 2 degrees. " We can be cautiously optimistic about the direction of these trends, but we must also realize that technology alone will not save us – says Hausfather -: without more incisive policies that favor its adoption, we will not be able to achieve our goals ".

The new IPCC report falls in the middle of these scenarios: It warns that unless policymakers are much more ambitious in pursuing a reduction in temperatures, we could be heading for a rise of about three degrees by 2100. Given the severity of the environmental damage we are already recording with a warming of 1.1 degrees, we would be facing an unsustainable escalation.


For Hausfather there are reasons to hope that averting this future is possible. Last year, the United States passed the Inflation Reduction Act, which allocates hundreds of billions of dollars to stimulate the green economy and incentivize American citizens to make their homes more energy efficient. The invasion of Ukraine has forced Europe to turn away from Russian gas and adopt cleaner technologies, such as heat pumps. “What China is doing with electric vehicles is huge,” adds Hausfather, referring to the rapid adoption of electric mobility in the country. And with renewable energy prices falling, he continues, “solving this problem will likely be much cheaper than we thought a decade ago.”

The food system, however, will be more difficult to decarbonise. A study published earlier this month estimated that the sector alone could raise temperatures by one degree by 2100, but also pointed to the powerful levers that can be pulled to control emissions: three-quarters of that warming would come from high methane emitting industries such as dairy farming, animal husbandry (because of the notorious cow burps) and rice cultivation (bacteria that emit the gas grow in rice paddies). Methane is 80 times more potent than CO 2 but disappears from the atmosphere within ten years rather than centuries. Changes such as reducing demand for beef or developing feed additives that prevent cows from emitting methane could help reduce warming rapidly.

Decarbonization also brings other benefits, known as "multi-solution ": adding green space to a city, for example, absorbs more carbon dioxide, freshens the air, mitigates flooding, improves mental health, and can enable urban dwellers to self-produce more food, increasing food security while reducing emissions from transport. Switching from petrol-powered cars to electric vehicles cuts the amount of CO 2 on the road and also cuts air pollution: "This transition to net zero emissions is hugely beneficial to public health around the world," says Elizabeth Sawin, founder and director of the Multisolving Institute, which deals with climate solutions.

The latest IPCC report comes at a time when humanity is facing a crossroads: to continue on the same path as always or accelerate the green revolution. " If we act now – said IPCC President Hoesung Lee in a statement –, we can still guarantee a sustainable and livable future for all ".

This article originally appeared on US.

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