Left to the processes of nature, Homo sapiens may have survived for a few more million years on this planet, but the effects of anthropogenics are ensuring that we may just have a few dozen years left.
Stephen Hawking famously predicted that by 2100 there would be no humans left on Earth, but what has caught the attention of environmentalists globally of late is the much more frightening forecast by Guy McPherson, a professor at the University of Arizona.
He says the sixth mass extinction has already begun: by 2028 the temperature of the planet will have far exceeded the two degree cap projected by the Intergovernmental Panel on Climate Change as the final climate frontier—the earth will be the hottest it has been in two billion years.
As the Arctic ice disappears, its permafrost (which forms 24 per cent of the world’s land mass) will melt, releasing billions of tonnes of carbon dioxide, methane and hydrogen sulphide into the atmosphere, accelerating the heating process. By 2036, temperatures will have gone up by seven degrees, oxygen will dissipate and mankind will be dead. No one has as yet refuted McPherson’s prognostications scientifically, for they are based on verifiable and measured data. Atmospheric concentration of carbon dioxide has reached 400 ppm (the tipping point is 450, at which point nothing we do will make a difference), temperatures are already more than one degree above pre-industrial levels and will reach three degrees even if we abide by the Paris Agreement targets.
All scientists agree that the Arctic is the bellwether for all future climate change and the news from there is not good; the Arctic is warming at twice the global rate; its volume of ice has fallen by three quarters; Greenland is losing 375 billion tonnes of ice every year. McPherson is not exaggerating about the catastrophic effects of the melting of Arctic ice and inevitable unfreezing of its permafrost: half of the stored carbon dioxide in the planet lies under it.
There is a double whammy here: melting ice will raise sea levels, dilute the salinity of the oceans and alter the rotational cycle of currents which also determine weather patterns like El Nino; the release of humungous quantities of carbon dioxide and methane into the atmosphere will speed up the process of global warming. The professor may be off by a few years, but not by much. The IPCC’s postulation that all will be well if we restrict the rise in temperature to two degree Celsius suffers from two infirmities: it does not take into account the release of the carbon dioxide and methane stored under the Arctic permafrost and its impact on heating of the planet. Second, it addresses only the flow of carbon dioxide and not its existing stock.
This is a critical omission which may invalidate all its futuristic models. Of the 116 models suggested by the IPCC to reach the goals of the Paris Accord, 101 assume “negative emissions”. But that is only possible if (a) the current flow of greenhouse gases (40 billion tonnes per annum) is reduced to zero, and (b) the existing stock already in the atmosphere is also systematically depleted in a time-bound manner. Neither is happening. Last year the total emissions increased by two per cent on the back of a global economic revival. As regards the existing stock, IPCC assumes that 810 billion tonnes of carbon will be sucked out of the air by 2100— even if we start doing so by 2020 this would mean reducing the stock by 10 billion tonnes every year. Currently the world does barely 40 million tonnes! This is the crux of McPherson’s argument: even if we reach zero emissions we will be unable to liquidate the stock and the warming will continue. The only solution to avert certain disaster is to adopt NETS (negative emission technologies) which not only involve cutting emissions but also creating new carbon sinks or extraction mechanisms for the existing stock of carbon dioxide. Unfortunately, this is not getting the attention it deserves— it was not even discussed at the Bonn conference last November! Removing 10 billion tonnes carbon from the air every year is a stupendous task which will challenge the political will, financial and technical resources of even the most developed countries.
A multi-pronged approach will be necessary. The best method for carbon capture, obviously, is what nature had devised before we upset the natural balance— reforestation and afforestation— but this requires a huge area of land: 3.2 million sq. kms or another India. This is just not available, and trees require a long time to grow and reach their optimum sequestration potential. It also does not help that we deforest 29.70 million hectares of green cover every year (2016 figures), an area equivalent to the size of New Zealand. Other steps will be needed: change in agricultural practices to stimulate the soil to store more carbon, introduction of alkaline solutions in the oceans to make them absorb more carbon, extraction and capture of carbon directly from the air by installing huge mechanical plants. None of this is happening yet. This will need humongous amounts of money (one estimate says that just for R&D about $50-60 billion will be required each year).
Private investment in NETS will not be forthcoming unless there are profits to be made, just as investment for renewables picked up only when the demand for green power increased. Governments, therefore, will have to create a policy and tax environment to fast track investment in, and operation of, NETS. One way could be to impose a carbon tax across the board and use these funds to subsidise NETS. Norway has shown how this can be done: it imposes a carbon tax of $50 per tonne emitted if oil companies don’t capture it. Some of them have found a cheaper way of pumping the carbon back into the soil—in other words, the tax has stimulated these companies to adopt NETS. The way forward is clear, and so is the time frame. The year 2036 is not all that far away.