It's not the first time thousands of academics have united to urge people to take action on climate change. More than 11,000 scientists from 184 countries published a letter in 2017, warning that "human beings and the natural world are on a collision course".

By Ian Horswill


Posted on November 6, 2019

How many scientists does it take to convince political leaders and leaders of industry across the world that the situation with climate change is real and only going to get worse unless action is taken? Not enough, it seems.

On the 40th anniversary of the first world climate conference, which was held in Geneva in 1979, more than 11,000 scientists from 184 countries led by Bill Ripple, and Christopher Wolf, of the Department of Forest Ecosystems and Society at Oregon State University, wrote in BioScience: “Scientists have a moral obligation to clearly warn humanity of any catastrophic threat and to tell it like it is.”

“On the basis of this obligation and the graphical indicators presented below, we declare, with more than 11,000 scientist signatories from around the world, clearly and unequivocally that planet Earth is facing a climate emergency.”

Phoebe Barnard, a lead author of the report and the chief science and policy officer at the Conservation Biology Institute, a nonprofit science group in Oregon, told CNN the report makes it clear that “there’s no more wiggle room” for policymakers.

“Posterity will remember them badly for dismissing climate change as a serious threat to our civilisation,” she said.

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Climate change

It’s not the first time thousands of academics have united to urge people to take action on climate change. More than 16,000 scientists from 184 countries published a letter in 2017, warning that “human beings and the natural world are on a collision course”.

The latest report said the climate crisis is “closely linked to excessive consumption of the wealthy lifestyle”.

“Despite 40 years of global climate negotiations, with few exceptions, we have generally conducted business as usual and have largely failed to address this predicament,” they said.

The scientists listed six key issues that need to be addressed if humanity wants to prevent the most catastrophic scenarios.

  1. Population: Still increasing by roughly 80 million people per year, or more than 200,000 per day, the world population must be stabilised — and, ideally, gradually reduced—within a framework that ensures social integrity. There are proven and effective policies that strengthen human rights while lowering fertility rates and lessening the impacts of population growth on GHG emissions and biodiversity loss. These policies make family-planning services available to all people, remove barriers to their access and achieve full gender equity, including primary and secondary education as a global norm for all, especially girls and young women.
  2. Food: Eating mostly plant-based foods while reducing the global consumption of animal products, especially ruminant livestock, can improve human health and significantly lower GHG emissions (including methane in the “short-lived pollutants” step). Moreover, this will free up croplands for growing much-needed human plant food instead of livestock feed, while releasing some grazing land to support natural climate solutions. Cropping practices such as minimum tillage that increase soil carbon are vitally important. We need to drastically reduce the enormous amount of food waste around the world.
  3. Energy: The world must quickly implement massive energy efficiency and conservation practices and must replace fossil fuels with low-carbon renewables and other cleaner sources of energy that is safe for people and the environment. We should leave remaining stocks of fossil fuels in the ground and should carefully pursue effective negative emissions using technology such as carbon extraction from the source and capture from the air and especially by enhancing natural systems. Wealthier countries need to support poorer nations in transitioning away from fossil fuels. We must swiftly eliminate subsidies for fossil fuels and use effective and fair policies for steadily escalating carbon prices to restrain their use.
  4. Nature: We must protect and restore Earth’s ecosystems. Phytoplankton, coral reefs, forests, savannas, grasslands, wetlands, peatlands, soils, mangroves, and seagrasses contribute greatly to sequestration of atmospheric CO2. Marine and terrestrial plants, animals, and microorganisms play significant roles in carbon and nutrient cycling and storage. We need to quickly curtail habitat and biodiversity loss, protecting the remaining primary and intact forests, especially those with high carbon stores and other forests with the capacity to rapidly sequester carbon (proforestation), while increasing reforestation and afforestation where appropriate at enormous scales. Although available land may be limiting in places, up to a third of emissions reductions needed by 2030 for the Paris agreement (less than 2°C) could be obtained with these natural climate solutions.
  5. Economy: Excessive extraction of materials and overexploitation of ecosystems, driven by economic growth, must be quickly curtailed to maintain long-term sustainability of the biosphere. We need a carbon-free economy that explicitly addresses human dependence on the biosphere and policies that guide economic decisions accordingly. Our goals need to shift from GDP growth and the pursuit of affluence toward sustaining ecosystems and improving human well-being by prioritising basic needs and reducing inequality.
  6. Short-lived pollutants: We need to promptly reduce the emissions of short-lived climate pollutants, including methane, black carbon (soot), and hydrofluorocarbons (HFCs). Doing this could slow climate feedback loops and potentially reduce the short-term warming trend by more than 50% over the next few decades while saving millions of lives and increasing crop yields due to reduced air pollution. The 2016 Kigali amendment to phase down HFCs is welcomed.
  7. The report was published in the week that the US formally began the process of leaving the Paris Agreement, the global climate change accord. The US government stated the Paris Agreement puts an “unfair economic burden” on American people.

    The Paris accord, agreed in 2015, committed the US and 187 other countries to keep rising global temperatures below 2C above pre-industrial levels and attempting to limit them even more, to a 1.5C rise.