World Scientists’ Warning of a Climate Emergency – take it seriously!

Two years ago, over 15 thousand scientists signed the “World Scientists’ Warning to Humanity: A Second Notice,” about our interlocking global ecological crises. This year, 11 thousand scientists endorsed the new “World Scientists’ Warning of a Climate Emergency”, published November 5th in Bioscience magazine. Will world leaders and citizens take notice, come together, and act with the force and foresight our situation demands?

By Patrícia Dérer

The climate crisis is accelerating faster than many scientists expected. In a new World Scientists’ Warning of a Climate Emergency, William Ripple and colleagues around the world warn policy makers and the rest of humanity that we remain on a “business as usual” trajectory. This means that, despite 40 years of climate negotiations, we have not changed our trajectory towards a major climate disruption (Figure 1).


Figure 1. Climatic response time series from 1979 to the present. Rates shown in panels are the decadal change rates for the entire ranges of the time series. Source: Ripple et al. 2019

Ripple et al. provide substantial, alarming evidence of continuance of an ecologically degrading status quo. This includes increasing greenhouse gas emissions into the atmosphere (CO2, methane), increasing global surface and ocean temperatures, more frequent extreme weather events and associated damage costs, sea level rise and increased ocean acidity, and shrinking ice masses in Antarctica, Greenland, and at glaciers worldwide (Table 1).


Table 1.  Summary of climatic response indicators. Table columns show the variable name, the most recent year with data, the value of the variable in that year, the rank for that year (rank #1 is the highest possible value), and the total number of years with data (since 1979). For example, atmospheric carbon dioxide concentration was most recently estimated in 2017 to have a value of 405 parts per million, which ranked as the greatest value among the 38 years of data available since 1979. Source: Ripple et al. 2019

We live in a decade of dangerous and harmful records. Despite the conferences, summits and agreements over the last 40 years alerting the world to an impending climate catastrophe, humanity continues to set more alarming, harmful records. 2017 was the year of record high oil and natural gas consumption, record per capita meat consumption and record air transport, ultimately leading to the highest annual GHG emissions in human history (Figure 2; Table 2.).

Table 2. Summary of human activity indicators. Table columns show the variable name, the most recent year with data, the value of the variable in that year, the rank for that year among all years with data since 1979, and the total number of years with data since 1979. Source: Ripple et al. 2019

Human population numbers are also at a record high. They are still growing by more than 80 million people per year, concomitantly with energy, food and transportation demands. There are some encouraging signs, like the expansion of solar and wind energy, consumption of which has increased 407% per decade. Yet in 2017, solar and wind use was still 32.5 times smaller than fossil fuel consumption (combined gas, coal, oil) (Figure 2).

Figure 2. Change in global human activities from 1979 to the present. All these indicators are linked to climate change, either as cause or effect. Source: Ripple et al. 2019

Ripple and colleagues list “six critical and interrelated steps that governments and the rest of humanity can take to lessen the worst effects of climate change”. Like the first “World Scientists’ Warning to Humanity” in 1992, they emphasize that we must end population growth and ideally reduce human numbers, gradually and in ways that respect human rights. This is because anthropogenic climate change is primarily driven by economic and population growth.

There are proven, effective and efficient policies and actions that lower fertility rates, primarily through the avoidance of unintended pregnancies. The Overpopulation Project highlights these policies in our series of blogs on family planning success stories from around the world, and in our list of solutions to overpopulation. Key solutions include removing barriers to contraception access, improving family planning and sex education, increasing educational opportunities generally, and banning child marriage. These policies are not only slowing down population growth, but empowering women, tackling gender inequality, and helping to alleviate poverty around the world right now. We need to increase funding and commitment to these efforts!

We hope the new “World Scientists’ Warning of a Climate Emergency” will garner as much attention as the recent “World Scientists’ Warning: A Second Notice”. The latter made global headlines and was cited by 150 news outlets, including CNN, the BBC, Fox News, and on page 1 of Le Monde. It was one of the most talked about papers published since global Altmetric records began, but it isn’t clear how much impact it actually had on public policies and human behaviour. As Ripple et al. state, we need bold and drastic transformations of our economic and population policies.

The fact that some governments are declaring a climate emergency is a hopeful sign of change; so is the emergence of large grassroot citizen movements such as Extinction Rebellion. Unfortunately, in terms of population policies, much remains to be done. The human right to contraception continues to be violated in many places. One-quarter of all women around the world who want to stop or delay childbearing cannot access contraception, due to political, socio-cultural, or religious barriers. This unmet need contributes to an unacceptably high rate of unintended pregnancies of 40%.

Climate March 21/09/14 - 11
Photos taken at the climate march in London on 21st September 2014.

As Ripple et al. note, when people come together to work on a problem, they can make a huge impact. This has been demonstrated in response to scientists’ discovery of ozone depletion: the policies enacted following scientists’ alarms has led to a recovery of Earth’s ozone layer. Can we achieve a similar success in the case of a much more complex issue, climate change?


Do you want to learn more about the solutions for overpopulation and actions towards sustainability? What actions we need to take on individual, community, national and global level? Check out The Overpopulation Project’s list of solutions!

One thought on “World Scientists’ Warning of a Climate Emergency – take it seriously!

  1. No, we cannot achieve a similar success. Humans lack any semblance of a regulatory structure, and so it will be fossil fuel extraction and production until the destruction can no longer continue.

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