Since the Paris Agreement came into force in late 2016, the scientific community has been working to compile the latest data on the impacts of Climate Change and the potential future greenhouse gas emissions pathways to put the brakes on global warming. The Paris Agreement’s invitation to the International Panel on Climate Change (IPCC) was specific to the impacts of holding global warming to a 1.5oC increase above pre-industrial levels. 1.5oC was (and still remains) the goal agreed to by almost every nation in the world, and thought to be enough to hold off the most dangerous impacts of Climate Change and limit the risk of irreversible changes to the world’s ecosystems.
The IPCC’s response, in its Special Report on 1.5 Degrees Celsius (SR15) released this month, has gone a step further and detailed the differences between the impacts on the planet from a rise of 1.5oC and a 2oC increase. While, predictably, 2oC is worse, what is alarming in the IPCC report is that an increase of 1.5oC will have more serious impacts than originally thought. The world is already approaching 1oC warmer than it was during pre-industrial times, and even that smaller gain, with greater and greater scientific confidence, is amplifying the intensity of extreme weather events, rising sea levels, and melting glaciers and sea ice among many disturbing trends. Further increases, particularly as the world approaches a 2oC rise, risk the loss of nearly all the world’s coral reefs, frequent loss of all sea ice over the Arctic in summer, a greater decline in biodiversity and declining agricultural yields for grains, such as wheat and maize.
Equally alarming in the IPCC report is that the current voluntary commitments to limit greenhouse gas emissions by the nations of the world is not enough for even the 2oC target. Emissions continue to rise globally, with the current pathway leading to a 3oC increase by the end of the century. To change this course will take a transition in energy technologies, land use, urban and infrastructure design and industrial systems on an “unprecedented” scale, all of which may be constrained by political, economic, social and technological issues.
The IPCC’s SR15 also addresses how much time the world has left before an overshoot of the 1.5oC target at current emissions rates becomes inevitable. Policymakers tend to refer to the somewhat simplified “Carbon Budget” as it’s an easy number to process and has a correlation with temperature rises. This Budget refers to the amount of cumulative greenhouse gases allowable in the atmosphere (often expressed in Gigatonnes of Carbon Dioxide) before reaching various thresholds. Under current commitments, the world will lock in a 1.5oC rise from pre-industrial levels in approximately 12 years (or by the year 2030). And 2oC by 2050. This makes a review of the country-by-country emissions reductions commitments even more important, with scientists advocating for global decreases in emissions of nearly 50% by 2030 over 2010 levels, and a world that has net zero emissions by 2050.
Unfortunately, very few believe our dependence on fossil fuels, a significant contributor to emissions, and our cultural habits, such as meat-based diets, will change in the extraordinary ways required. Many countries are hiding behind the perceived economic disadvantages of the transition to a low-carbon future. Countries such as Australia are still pushing coal, one of their main export industries. China’s emissions have also started to grow again after several years of more stable output in the wake of increasing demand for automobiles and energy. And the announced US withdrawal from the Paris Agreement, to take effect in November, 2020, hasn’t helped either.
Ultimately, almost any pathway to limit the worst impacts of Climate Change will literally require sucking carbon out of the air (similar to the way that trees function) and has galvanized proponents of Direct Air Capture (DAC) and Carbon Capture, Utilisation and Storage (CCUS) technologies. Creating not just a carbon neutral world, but one that includes negative emissions in the future may be the last great hope. Even that, however, is fraught with the unknown consequences of geo-engineering the planet.
Featured Images: IPCC Special Report