I have been extremely busy lately and therefore running completely behind on my writing schedule. If that was not enough, the IPCC decided to publish another of its so-many-hundreds-of-pages-counting reports on climate change. This time I decided to not even start reading the executive summary. Why, you ask? Because I am getting so damn tired of reports, press conferences, talks, climate summits, and what not the Intergovernmental Panel on Climate Change has been dropping on us since the first global Earth Summit in Rio in 1992.

The cover of the IPCC’s latest special report on global warming.

A lot has changed since then. On the one hand, greenhouse gas emissions skyrocketed while the world economy was booming. On the other hand, renewable energy technologies have grown from a niche resource to the cheapest technology for new power plants.

What did not change since the beginning of the nineties is the bottom line of climate scientists’ warning: human activities are accelerating natural warming processes to an alarming speed with potentially disastrous results. A.k.a. anthropogenic climate change. But in fact, even in 1992 that was kind of old news.

Back in the summer of 1979, a number of leading US scientists gathered in a mansion in Cape Cod, Massachusetts, to review the growing pile of scientific data and research on manmade climate change and to decide whether the White House should take immediate action.

One of them, Syukuro Manabe, who was the first to model the greenhouse gas effect in his lab at Princeton, predicted a warming of 2 degrees over the 21st century. But, there were many reasons for uncertainty. If the group were to present the results to the President himself, they needed confirmation from other models.

They called up a young scientist of Yale University named James Hansen, who previously studied the atmosphere (and greenhouse gas effect) on Venus. He had now run his computer models on Earth assuming twice as much carbon emissions in 2035 compared to 1979. The simulation result: four degrees of warming by 2100.

James Hansen started his career studying the atmosphere of Venus. He then applied his knowledge on Earth’s atmosphere and became a leading climate scientist. In recent years he has become a climate activist calling for urgent action (photo: Milan Ilnyckyj)

Where did the discrepancy between the two calculations come from, everybody wondered. One of the other scientists present, Akio Arakawa, was a pioneer in computer modelling and analysed the results of Hansen and

Manabe until late at night. He finally realised what caused the difference: Manaba had given too little weight to the effect of melting sea ice, Hansen too much. The best estimate should lie in between: 3 degrees. A warming, everyone at the gathering agreed, would turn the world in a scorching oven.

When world leaders pledged their contributions to the Paris Agreement in Paris 36 years later, scientists were quick to estimate that if all of them would be implemented, we still would end up with 3.6 degrees warming by the end of this century.

What we really needed in December 2015 is a doubling down of the pledged efforts and a concrete action plan. What the policymakers did instead: request yet another report.

Cheering at the end of COP 21 in Paris, where 175 countries agreed to take action on global climate change. Pledges under the framework of the Paris Agreement are far from sufficient to limit global warming to 2 degrees (photo: Francois Mori / AP)

The bottom line of the report is the following: we have 12 years left to undergo a complete paradigm shift if we want to have a slight chance of limiting global warming to 1.5 to 2 degrees by the end of the century. In fact, we have reached the point where we put enough carbon into the atmosphere to guarantee ourselves of 2 degrees of warming, unless we succeed in becoming carbon neutral by 2050 and even take CO2 out of the air. To get there we need to reduce global emissions at least 45% by 2030 compared to 2010 levels.

45% in three legislative terms. Good luck. Politicians did not succeed in putting up a coherent and strong framework for guaranteed emission reductions over the last four decades. I doubt if they can do so now in one.

Does that mean I am throwing my arms up, that I am giving up? No, not at all. More than ever I believe in mankind’s ingenuity to find solutions, both technological and social, to tackle its greatest challenges. 12 years ago there were little believers of wind and solar. 12 years ago vegetarians and vegans were a tiny (somewhat ridiculed) minority in the meat-eating countries of this world. 12 year ago no-one had ever heard of the term circular economy. 12 years ago no-one was thinking twice about the impact of their travels.

Businesses and citizens’ movements are eager and able to do things –fast. That’s exactly what we need right now. Enough talking, time for action. If we don’t do it, no-one will.