There is overwhelming consensus within the scientific community, based on independent evidence from multiple sources, that the ongoing global warming is caused by rising levels of CO2 in the atmosphere. Most alarming is the accelerating retreat of planetary ice, particularly in the Arctic, which happens to be the fastest warming region on the globe. The 3,000 metre thick Greenland ice shield has been melting for many years, with two independent factors in operation accelerating the rate of melt: warming of the Arctic Ocean due to the steadily diminishing sea-ice cover and the fall in altitude with declining thickness of the ice shield. Complete melting of the Greenland ice mass will raise global sea levels by six metres. Ongoing thawing of the permafrost of the circum-Arctic tundra will release the trapped greenhouse gases, CO2 and methane, in quantities that would greatly accelerate the current rate of warming.
Heat waves increasing in intensity, greater frequency of freak weather events and rising sea levels are inevitable outcomes of global warming. Sea level rise is the most dangerous as it will inundate coastal cities, push estuaries upriver and displace hundreds of millions of people all over the world. Resettling these climate refugees will put enormous strain on the moral and material fabric of humane civilisation; I hesitate to dwell on that nightmare and prefer to think about what could be done now to avert it.
Sea level rise is a new concept in human history because coastlines have been anomalously stable over the last 10,000 years. The sea still laps at the shore of Lothal in Gujarat, the bronze-age harbour contemporaneous with the Harappan civilisation of 4,500 years ago. However, in the 5,000-year period between 15,000 and 10,000 years ago, when the last Ice Age came to an end and the ice shields covering northern North America and parts of Eurasia melted away, the sea level rose by 130 metres!
In the same period, atmospheric CO2 concentrations increased from 0.018 to 0.028 per cent and remained as anomalously stable as the sea level until the end of the 1900s. Since then, with the dawn of the Industrial Age, they have steadily increased, and in 2016 crossed the 0.04 per cent level.
In the space of a century, humans have added more CO2 to the atmosphere than accumulated there in the 5,000-year period of the Big Melt. So it is not surprising that we have started the next Big Melt which, if left unchecked, will thaw the remaining ice shields and raise sea levels by about 100 metres. There are maps on the web that show what this does to the planet’s geography.
When confronted with the inevitability of sea level rise, the big question that arises is: how much time do we have? The answer depends on what global humanity does in the coming years. If we continue burning fossil fuels and do nothing about removing CO2 from the atmosphere, large-scale resettlement programmes for people evacuated from the low-lying fringes of coastal cities and deltas will have to start well before mid-century, i.e. when today’s children reach the primes of their lives. There is hope that the deadlines can be postponed if countermeasures are adopted on a war footing as soon as possible. Ratification of the Paris Accord by so many countries, including India, is no doubt a heartening milestone, but its goals fall short of what is required now. Attempts by the next US administration to change course on the climate front will be met by stiff internal opposition from an administration committed to combating climate change. This is where India, which prides itself on being the oldest continuous culture on the planet, should take up a leadership role and chart the course for a brighter future.
I perceive four fronts along which decisive action in India could be taken now: 1) developing a massive climate education campaign directed at people from all walks of life that explains the nature of the dangers to society lying ahead, their causes and consequences, and how these can be averted or at least mitigated; 2) curbing greenhouse gas emissions from burning fossil fuels by switching to regenerative energy sources, in particular solar and wind; 3) developing a portfolio of approaches to remove CO2 from the atmosphere; 4) exploring innovative techniques to ensure long-term, sustainable food security. I deal briefly with each of these points in the following.
Understanding a problem is a prerequisite to solving it in the long term, and since motivated public participation is crucial for the success of this gargantuan undertaking, a climate education campaign, tailored to the situation in India, is the way forward. The type of public education campaign I am advocating is analogous to, but on a much grander and more urgent scale than, that implemented in the past decades for disease control and public health improvement: despite many shortcomings, their overall success is undisputed. Earth system scientists are making rapid advances in understanding how the climate machinery of our planet works. Their predictions of the effects of global warming are being confirmed by unfolding reality. The stories emerging from the various research fields, greatly aided by state-of-the-art computers, are exciting and worthy of broad public attention as they make sense in unexpected ways. They can be transmitted to the public by a combination of lectures, movies and animations on the web. The media and entertainment industry could play major roles in drawing attention to the problems ahead and how to solve them now. A major thrust of the campaign would be to teach cyclical thinking, for which the hydrological and carbon cycles of our planet provide the blueprint for deeper understanding. Cyclical thinking is the philosophical framework of sustainability and goes far beyond linear thinking, which is short-term, limited to the space/time scales of the thinker and the cause of our current problems. It is worth pointing out here that the concept of cycling is deeply entrenched in ancient Indian philosophy.
The vast improvement in public health and the quality of life has been driven by burning fossil fuels. India has paid a heavy price in terms of terrible air quality and its adverse effects on the health of people, particularly children. Will the babies born today have breathing problems when they grow up? Is not the dream of phasing out internal combustion engines from the cities and replacing them with electric engines within reach? The process of countrywide electrification offers enormous growth potential and employment for a workforce ranging from unskilled labour to highly trained experts. The technology for implementing the transition to decentralised energy capture is already developed, so why wait for the future? The vision of a solar-powered India is the type of decentralised self-sufficiency that Gandhi dreamed of and that is now within reach of the entire population, rendered possible by modern, smart technology. There is enormous scope for innovation in the field of solar-generated electricity and its storage, which will lead to creation of new products for new markets. The Indian diaspora could be persuaded to contribute to this monumental effort.
In this bright new light, investing in nuclear power plants is repeating the same mistake made at the dawn of the fossil fuel era-disregard of the fate and future impact of the waste products. Radioactivity is a form of energy humans cannot feel, hence easily misjudge. Germany is currently facing the onerous task of dismantling its reactors and disposing of their wastes. Apart from the enormous costs to be borne by the taxpayers, deciding where to bury them within the country is going to cause strife. India should be writing a new verse for Surya Namaskar (salutation to the sun) rather than burdening coming generations, labouring under increasing pressure from global warming, with spent nuclear reactors.
Other than planting trees, removing anthropogenic CO2 from the atmosphere is an unpopular topic in the scientific community, particularly as it’s believed that research in this field will distract from the primary task of cutting emissions. The analogy that comes to mind is that of a leaking ship already listing because the officers have decided not to let the crew start bailing out the water until the leak is repaired. That CO2 removal can never be an option for curbing emissions is illustrated by the magnitude of the problem. The mass of excess carbon in the atmosphere, as CO2, that would have to be removed to restore initial conditions (the difference between 0.028 and 0.04 per cent) is equivalent to 250 billion tonnes. For comparison, the total amount of carbon present in all the visible vegetation present on the continents, including crops, grasses and forests, is 500 billion tonnes. Where will the space, water and nutrients to increase vegetation cover by that much come from? For me, the answer lies in the vast deserts of the ocean-the subtropical gyres that cover half the planetary surface but barely contribute to food supply or carbon sequestration.
Alternative, secure sources of food will also need to be developed. My expertise lies in the oceans, and that is where humankind will have to turn to for creating artificial ecosystems by aquafarming in the ocean’s deserts. These are vast lenses of warm water about 200 metres deep, floating on nutrient-rich cold water that fills the oceans. The oases would be maintained by pumping nutrient-rich deep water to the surface layer where, after it has warmed, plankton productivity would feed fish and could also be used to grow seaweeds for consumption as well as for carbon sequestration. Local energy sources could accomplish the task. Such an undertaking will entail enormous infrastructure of pipes and anchored islets and will be an engineering challenge worthy of the smart era of technology that we have now entered. The alternative sources of food provided by aquafarming on the open ocean will not only release pressure on the present agricultural land and enable decongestion of cities, but also provide space for natural ecosystems to expand and sequester carbon. Instead of dreaming about space travel, we should be directing our attention to the unused inner spaces on our planet. Needless to say, India is well placed to launch such a venture.