“The latest report on climate change makes grim reading” magazine the Economist headlines referring to the latest IPPC report from October 8th 2018. With the world underway to 2 or 3 degrees of global warming, the report seeks to answer if 1,5 degrees is still feasible. The report, written by 91 researchers from 41 countries presents no new science but rather confirms what the half-degree difference between the two targets may mean for the planet, and regarding the effort needed to meet the tougher goal. The authors profess “high confidence” of a “robust difference” between 1.5°C and 2°C worlds. At 1.5°C, 6% of insect species, 8% of plants and 4% of vertebrates would lose more than half their habitat. The figures for 2°C are 18%, 16% and 8%, respectively.
At that temperature rise, ecosystems covering between a twelfth and a fifth of Earth’s land mass can be expected to undergo a transformation to another type—savannah to desert, say. That is 50% more than would happen with a rise of 1.5°C. Most dramatically, the IPCC finds it almost certain that a 2°C rise would wipe out more than 99% of corals. By contrast, a rise of 1.5°C would leave 10-30% of them alive, and with them the hope of regeneration if temperatures subsequently stabilized. Permitting a rise of 2°C rather than 1.5°C could also see 420m more people exposed regularly to record heat. Several hundred million more would have to contend with climate-induced poverty. Food security would decline and water scarcity will increase, especially in poor and already-fragile areas such as the Sahel region of Africa, just south of the Sahara desert. Moreover, an additional 10cm of sea-level rise could hurt the livelihoods of more than 10m people living on the coast. The report also nods towards the chance of dangerous feedback loops. A two-degree temperature rise could lead to the thawing of 1.5m-2.5m km2 of permafrost—about the area of Mexico. That, in turn, would release methane, a potent greenhouse gas which would lead to further warming, thawing and so on.
The report outlines possible pathways to a 1.5°C future. On the bright side, the IPCC concludes that such a future remains geophysical within reach, thanks to what remains of the Earth’s “carbon budget” for 1.5°C—the cumulative sum of emissions at which the climate system stands a good chance of remaining below a particular temperature. These “negative emissions” could come from planting more forests, which draw in carbon dioxide as they grow. Planting “energy crops” such as fast-growing grasses, which could be burned instead of fossil fuels (with the carbon dioxide thus generated captured and stored underground), is also possible. Either approach, though, would mean converting to that purpose an area of agricultural land somewhere in size between India and Canada. An alternative is “direct air capture”—artificial devices that retrieve carbon dioxide directly from the atmosphere. These exist but they, too, would need to be deployed at a gargantuan scale, with challenging economics.
Negative emissions or solar geo-engineering might ease the need to decarbonise economies quickly—but not eliminate it. Even with negative emissions carbon-dioxide release still needs to fall by 45% or thereabouts by 2030. To have any hope of achieving this, two-thirds of coal use must be phased out in little more than a decade. By the middle of the century virtually all electricity must come from carbon-free sources (up from a quarter today), and all cars will need to run on electric motors (up from one in 500), as will trains and most ships.
Some of the technology needed to achieve this (solar panels, nuclear-power plants, electric cars and so on) is around, but not all of it. For aeroplanes to keep flying, either novel aviation bio fuel will need to be developed or negative emissions used to offset those from aircraft. Because cows produce lots of methane people will either have to switch to laboratory-grown burgers or change diets.
Facts on climate change are perhaps tedious but important. Underlying the IPPC report is the idea of the Anthropocene — an era in which human activity has become a dominant influence on the planet. The report notes that the rise in global concentrations of carbon dioxide is 20 parts per million per decade. This is up to 10 times faster than any sustained rise in CO2 in the past 800,000 years. The previous epoch with similar CO2 concentrations to today’s was the Pliocene, 3m-3.3m years ago. We are the shapers of the planet now. This should transform how we think about our role and responsibility. Net global emissions will have to drop to to zero not long after 2040, and earlier for methane and nitrous oxide. Emissions from industry will have to be reduced with 75-90% by 2050, relative to 2010. This requires a combination of hydrogen, electrification, sustainable bio based feedstocks and product substitution. We start to see that the world will have to be set on a different growth and investment path. Technically perhaps possible, but politically highly challenging. Some politicians simply ignore the facts and do nothing, others recognise the facts and pretend to act by setting ambitious targets without clear strategies.
It is important to see that the scale of uncertainty is a reason for action, not against it. Even when it would become clear that emissions reduction and economical growth are at odds, posing important re-distribution of wealth issues. The chance of cooperative action looks slim but in climate change words are cheap, actions are eloquent and the right thing to do.
Met vriendelijke groet, Kind regards,
Fred van Beuningen