Epitomizing the disconnect between scientific warnings and human action, global temperatures are now on track to rise by an unacceptable 3.2 degrees Celsius from pre-industrial levels by 2030 while greenhouse gas emissions hit all-time highs. As the 25th session of the Conference of the Parties to the United Nations Framework Convention on Climate Change (COP25) meets in Madrid December 2-13, the big emitters need to commit to a U-turn in their emission trajectory to avert the extreme impacts that scientists project.
Leaders in the top emitting nations need to drive climate action in view of their high share in carbon emissions (Figure 1). The top 10 percent of countries (20 of them) make up 81 percent of global carbon discharges, starting with China, the United States, India, Russia, and Japan. Given the dominance of these large economies, their national policies make all the difference to whether we can expect a reversal in the carbon intensity of global economic growth. A recent U.N. report calls for a 7.6 percent a year emission decline for the next 10 years to limit temperature rise to 1.5 degrees Celsius from pre-industrial levels. Contrastingly, emissions have increased 3 percent over the past three years, led by the United States, China, and India.
To motivate far stronger steps, it would help to be convinced that the payoffs from switching to a low-carbon growth path far outweigh the costs of making the transition. The benefits of climate action include avoided damages from climate change. And there is growing evidence on the damages that can be averted by timely climate action. India, according to a World Bank estimate, could incur damages of 2.8 percent of GDP by 2050 in the current climate trajectory. A recent estimate places the loss from climate change from extreme weather events for 82 countries at 3 percent of GDP by 2050.
There are also costs to taking climate action. For instance, the cost of switching from fossil fuels to low-carbon sources of energy. These costs of acting, however, are much smaller than the above-mentioned costs of not acting. The costs of addressing the climate crisis rise with every delay in taking measures, thus placing a premium on timely responses.
Figure 1: Country shares of carbon dioxide emissions, 2019
Source: Union of Concerned Scientists
Past estimates, however, understate the true damages of climate inaction. For one thing, improved global elevation data show coastal levels and habitats to be much lower and therefore the risk of floods and storms much higher than earlier maps had suggested. Furthermore, we are also seeing climate-aggravating feedbacks that were not fully appreciated before. For example, temperatures are increasing energy consumption in air conditioning and refrigeration. Also, global warming is making forest fires more destructive, in turn contributing to new climatic extremes.
Armed with all this knowledge, the single biggest step the big carbon-emitting countries could take is to cut their fossil fuel combustion. Eliminating all subsidies to fossil fuel production and consumption is a part of this agenda. The IMF has been measuring the full extent of fossil fuel subsidies, now estimated to be in the order of $5 trillion.
Encouraging the use of renewable forms of energy is the other part of the equation. It is helpful that the price of renewables, especially solar and wind, has been declining and their competitiveness vis-à-vis fossil fuels improving. But renewables still account for just 11 percent of global energy consumption, compared with 80 percent for fossil fuels. Solar and wind need to overcome technical and logistical impediments on production, storage, and distribution. To counter this, strong policy support and subsidies—justified on grounds of their positive climate effects—could vastly increase their usage.
Underpinning the switch to a low-carbon growth path would be a sustained wave of public sentiment favoring bold climate action. The worldwide youth movement for climate action is a signal of the political changes that might follow. Politicians with strong climate agendas are making inroads in Europe and even in the United States, but this momentum needs to be kept up.
COP25 negotiators will undoubtedly sound the alarm on the imminent danger of climate inaction. But will that spur climate actions in time? COP25 must focus on the big emitters and elicit commitments from them on changing course. A new and different G-20 of the top carbon emitters needs to be called upon to take responsibility for reversing the dangerous climate trend and announce a U-turn in the climate trajectory.
On April 22, Samantha Gross discusses approaches for decarbonizing heavy transport and industry sectors of the economy at the 2021 Freedman Lecture hosted by the University of Massachusetts Amherst.