The 1.5 degrees Celsius warming target has received considerable press along with the El Niño this year. Reports claimed that the planet could soon cross this temperature threshold due to this natural climate phenomenon.
But even if the world’s average surface temperature warms by more than 1.5 degrees Celsius for a year, nothing dramatically different may happen – other than the heatwaves, floods, droughts, and similar events that are already happening. The bigger question is: where is all the end-of-the-world messaging coming from?
Humankind might do well with less hyperbole about the climate crisis. It is a serious challenge today, yes, but a constant drumbeat of alarmist messages may only exacerbate climate anxiety and leave people feeling helpless – especially the young ones, who should be dreaming about saving the planet (or space travel) instead.
A questionable target
The target agreed to in the Paris Agreement, to keep the planet’s surface from warming by 2 degrees Celsius by the end of this century, has been touted as a monumental achievement, and it may well be if we actually manage to achieve this goal by 2100. But we must bear two things in mind. First, despite negotiations among the representatives of the world’s countries for more than two decades, global carbon emissions have shown no signs of slowing down.
Second, the 2 degrees Celsius target was not derived scientifically. The economics Nobel laureate William Nordhaus cautiously noted in the 1970s that a warming of 2 degrees Celsius above the pre-industrial level could render the planet warmer than it has ever been in several hundred-thousand years. He followed this claim up with a model of the socioeconomic impacts of crossing this threshold.
Some European politicians found this round number to be appealing as something to aim for in the 1990s, followed by climate scientists retrofitting their projected climate impacts to this warming level. Indeed, no sooner was this figure enshrined in the Paris Agreement than the Alliance of Small Island States demanded that it be lowered to 1.5 degrees Celsius. Once again, the climate community, now together with the socioeconomic-modelling community, retrofitted future scenarios to meet this so-called “aspirational” target.
Earth system models
Bringing science to serve society is a very noble goal, particularly when government officials demand scientific inputs for their decision-making. But many governments’ planned reliance on bioenergy and carbon-capture technologies to accomplish these goals do not consider the potential consequences of climate change on food and water security, for example – let alone the possibility that such promises have a long way to go before becoming viable.
It is also not entirely clear whether the earth system models (ESMs) that scientists use to prepare climate projections can reliably reproduce the consequences of a world that has warmed by 2 degrees Celsius but at the scale of the Indian subcontinent.
As of today, they certainly cannot do so accurately at scales smaller than the subcontinent, particularly for rainfall. So the question automatically arises: can they really distinguish between worlds warmer by 1.5 and 2 degrees Celsius? The answer is ‘no’, at least at the scales required to inform climate adaptation policy.
The uncertainties in climate projections will be dominated by ESM deficiencies for the next decade or two. For the decades beyond two, the assumed scenarios for radiative forcing, resulting from greenhouse gas emissions and socioeconomic choices, determine the warming levels and rates.
Uncertainties for India
This brings us to the next point: the impacts of the COVID-19 pandemic and Russia’s invasion of Ukraine have made it abundantly clear that it is very difficult for us to imagine all the possible socioeconomic and geopolitical events that matter to the well-being of our world, including its people. Even population projections may not hold considering China’s population is currently peaking and India is en route.
The physicist Niels Bohr once said that prediction is very difficult, especially if it is about the future. The best-case scenario, against this quote, is that climate projections cover all eventualities as well as all technological promises pan out, dragging the world’s emission rates down considerably by 2030, giving us a reasonable chance of staying below the 2-degree mark by 2100.
The inherent uncertainties, however, leave India, and the economically developing world, with some tough choices. This group of countries needs to develop its own tools to determine the crisis’s local impacts, especially for adaptation plans that deal with unavoidable consequences.
India in front
India’s engagement with the international community on climate mitigation, to try and avoid the unmanageable, should also keep an eye on any Frankenstein’s-monster experiments by richer countries, such as spraying dust in the upper atmosphere (a climate geoengineering solution that scientists know carries an unreasonable risk of droughts and crop losses).
More importantly, India should continue its leadership role by demanding that the community centred on the U.N. Intergovernmental Panel on Climate Change (IPCC) be prepared to improve projections that quantify impacts at local scales. The IPCC and India must also track climate change and its consequences continuously at the socially relevant timescale of a few years.
There is a real threat here of India ‘agreeing’ to colonise the future with imperfect models and unrealistic scenarios – especially when the paths to certain outcomes are based on technical and economic feasibilities and dubious concepts like “negative emission technologies”. The country must consider non-market goods such as equity, well-being, and biodiversity more deliberately.
As things stand today, reducing emissions as a paradigm for tackling climate change has essentially failed. Decarbonising the system is more likely to save us from ourselves. India can cash in on these opportunities and grow its economy by focusing on green technologies to decarbonise the future.
Raghu Murtugudde is a visiting professor at IIT Bombay and an emeritus professor at the University of Maryland.
