What if the fate of the world depends on worldwide decisions to be made by the end of 2015, yet few people know and even fewer care? I am not talking about a Hollywood blockbuster, like Russell Crowe’s struggle in Noah, but about something not so different. Instead of one great flood, humanity faces the likelihood that major weather disasters – extreme floods, droughts, heat waves, and hurricanes – will become far more frequent than in the past, disrupting food supplies, public health, economic growth and jobs around the world. Our last chance to avoid such a dangerous fate may be just around the corner, in Paris in December 2015.
Such a deadline may seem silly, yet it’s real. Here’s why. As the recent reports of the Intergovernmental Panel on Climate Change (IPCC) make clear, the current course of the world economy is filled with grave dangers. Human-induced greenhouse gases are rapidly warming the planet and already disrupting the Earth’s climate system. The world has repeatedly agreed to hold the line on the global temperature increase to less than 2 °C Celsius above the pre-industrial temperature. Yet the current economic trajectory puts the world on course to increase temperatures in the likely range of 3.7 – 4.6 °C by 2100.
The dangers of such a huge temperature increases are enormous. Not only will extreme weather events become more frequent, but various natural feedback loops could cause runaway climate disruption. As the Earth warms, the great ice sheets of Greenland and Antarctica may begin to disintegrate, potentially causing ocean levels to rise by several meters. The Amazon rainforest could die off as a result of repeated drought, thereby releasing massive amounts of CO2 into the atmosphere. Methane and CO2 buried in the permafrost in the tundra could also be released into the air as the tundra melts.
Some economists have shrugged their shoulders at such risks, blithely claiming that humanity will somehow adjust. Yet their casualness is belied by history. Yes, sometimes humanity adjusts successfully to shocks. Yet at other times, even small shocks can cause major disasters. Think of the assassination of the Habsburg Archduke Ferdinand exactly 100 years ago that helped trigger World War I. Or the banking failure that triggered the Great Depression, or the failure of Lehman Brothers that nearly brought down the entire world economy in 2008. Or the episodes of intense drought in Somalia, Sudan, Yemen, and Syria during the past 20 years that have contributed to mass migrations, violence and regional conflict.
The world is running out of time to deal with these risks. At the Rio Earth Summit in 1992, the world’s governments signed the UN Framework Convention on Climate Change (UNFCCC), pledging to “avoid dangerous anthropogenic interference in the climate system.” Yet the next 22 years have been dominated by finger pointing and squabbling rather than decisive action.
In recent years, governments have wisely defined “dangerous interference” as a rise in world temperature above 2 °C. Some great scientists, like my colleague Professor James Hansen, say that even 2 degrees is far too much for human safety. Yet despite the focus on the 2 °C limit, we are not even close to achieving it. With the world economy growing by 3 to 4 percent per year, and with China’s GDP growing at more than 7 percent per year, global emissions of CO2 and other greenhouse gases are soaring beyond safety.
The climate scientists speak of the “carbon budget” that can keep us to the 2 °C goal. Roughly speaking, we must keep the future cumulative emissions of CO2 below roughly 1 trillion tons. With annual emissions of around 35 billion tons per year, and rising, we have only around 30 years remaining at the current rate! In practice, the world should cut global CO2 emissions roughly by half – to around 15 billion tons annually – as of 2050, and to near zero as of 2080. This process is called “de-carbonizing” the global energy system.
Cutting emissions down to size will require huge, decisive, and coordinated actions by all major fossil-fuel producing economies – the US, European Union, China, Russia, GCC (the Gulf countries), Canada, and Australia. These countries need to cut their production, use, and exports of fossil fuels. The rest of the world, mostly importers of fossil fuels, will also need to shift from their dependence on fossil fuel imports to low-carbon energy sources such as wind, solar, geothermal, and nuclear power.
The 21st Conference of the Parties (COP) of the UNFCCC, scheduled for Paris in December 2015, may well be the last chance to strike the deal. According to diplomatic agreements reached in recent years, it is at the Paris COP21 that a new global agreement on de-carbonization is to be adopted. With the carbon budget nearly exhausted, a negotiating failure in Paris next year would likely to kill any remaining chance of avoiding a 2 °C rise in the global mean temperature. •
Admittedly the world today still seems uninterested and disengaged from serious climate negotiations. Yet the future habitability of the planet is at stake. Though climate change is still a “sleeper” in global politics, the high stakes in Paris will begin to penetrate the public mind in the coming months. Climate negotiations will rise in the political agenda and in the global media. Whether this happens fast enough to save the planet remains to be seen.
Jeffrey D. Sachs is Director of the Earth Institute at Columbia University and of the UN Sustainable Development Solutions Network. The SDSN will release a plan for global “deep decarbonization” in July 2014.