The declaration, published on November 5th in the journal BioScience, is based on scientific analysis of more than 40 years of publicly available data covering a broad range of aspects, including energy use, surface temperature, population growth, land clearing, deforestation, polar ice mass, fertility rates, gross domestic product and carbon emissions. “Scientists have a moral obligation to warn humanity of any great threat,” said Dr Thomas Newsome, a co-author of the paper from the University of Sydney. “From the data we have, it is clear we are facing a climate emergency.”
The authors point to the lack of action taken despite the many warnings issued in the past. “Exactly 40 years ago, scientists from 50 nations met at the First World Climate Conference (in Geneva 1979) and agreed that alarming trends for climate change made it urgently necessary to act. Since then, similar alarms have been made through the 1992 Rio Summit, the 1997 Kyoto Protocol, and the 2015 Paris Agreement, as well as scores of other global assemblies and scientists’ explicit warnings of insufficient progress,” they write in BioScience. “Despite 40 years of major global negotiations, we have generally conducted business as usual and are essentially failing to address this crisis,” said the co-lead author of the paper, Professor William Ripple from Oregon State University. “Climate change has arrived and is accelerating faster than many scientists expected.” He said that global surface temperature, ocean heat content, extreme weather and its costs, sea levels and ocean acidity are all rising. “Ice is rapidly disappearing as shown by declining trends in minimum summer Arctic sea ice, Greenland and Antarctic ice sheets, and glacier thickness. All of these rapid changes highlight the urgent need for action.” Other signs from human activities include sustained increases in per-capita meat production, global tree cover loss and the number of airline passengers. Encouraging progress of the recent past, such as decelerated forest loss in the Brazilian Amazon, may also halt since the pace of forest loss is likely to increase again under President Bolsonaro.
“While things are bad, all is not hopeless. We can take steps to address the climate emergency,” Dr Newsome said. The scientists have therefore outlined six steps humanity needs to take to reduce the impact of the emerging climate crisis. The first area of action is energy. We need to implement massive conservation practices; replace fossil fuels with clean renewables; leave remaining stocks of fossil fuels in the ground; eliminate subsidies to fossil fuel companies; and impose carbon fees that are high enough to restrain the use of fossil fuels. Another measure is to swiftly cut emissions of methane, hydrofluorocarbons, soot and other short-lived climate pollutants. This would have the potential to reduce the short-term warming trend by more than 50% over the next few decades, the scientists agree. Third, massive land clearing needs to be stopped. We need to restore and protect ecosystems such as forests, grasslands and mangroves, which would greatly contribute to the sequestration of atmospheric carbon dioxide. The fourth area of action is food. “Eat mostly plants and consume fewer animal products. This dietary shift would significantly reduce emissions of methane and other greenhouse gases and free up agricultural lands for growing human food rather than livestock feed,” the scientists recommend. They also call for a reduction in food waste.
Another step to avoid the climate crisis is to reduce the economy’s reliance on carbon fuels. Goals need to be shifted away from the growth of gross domestic product and the pursuit of affluence. “Curtail the extraction of materials and exploitation of ecosystems to maintain long-term biosphere sustainability,” the scientists urge. And finally, they recommend to stabilise global population, which is increasing by more than 200,000 people a day, using approaches that ensure social and economic justice. “Mitigating and adapting to climate change means transforming the ways we govern, manage, eat, and fulfil material and energy requirements,” the paper concludes. “The best news is that there is still time for people, policymakers and the business community to make the necessary changes to ensure that future generations can enjoy living on planet Earth, our only home,” Dr Newsome said. (ab)
