Only 6 G20 Countries Have Official Long-term Plans for Reducing Emissions. Here are 4 Reasons They Need Them by Katherine Ross Katherine Ross - October 22, 2018 Print Buenos Aires, Argentina The G20 meeting with take place in Buenos Aires, Argentina in November 2018. Photo by HalloweenHJB/Pixabay The latest science is clear: Global emissions must reach net-zero by mid-century if the world is to have a shot at limiting temperature rise to 1.5°C (2.7°F), the cap necessary for staving off the worst climate disasters. While G20 countries are responsible for about 75 percent of the world’s greenhouse gas emissions, only six of them have communicated official plans for how they’re going to reduce their emissions between now and 2050. The Paris Agreement invites countries to release their “long-term, low-greenhouse-gas-emissions development strategies” by 2020. These “long-term strategies” will be a topic of discussion at next month’s G20 Summit in Buenos Aires.
The images in the opening slide show are from the period when the rise in the earth's temperature was less than 1.0°C. We are now (May 2019) about 1.1°C average for the planet with some places lower and some much higher. If emission trends continue I expect 5°C or higher by the end of the century. How much higher depends on many variables and I discuss some of these below. The curve was made from a mathamatical power function that gave a best fit to the NASA data through 2017. It is similar to polynominal expansions made in Excel and to general trends from other methods. The target from the Paris Accords is 1.5°C and would represent a significant worsening of the climate. However, it is now almost universally accepted that achieving this is no longer possible and 2.0°C is unlikely without a very large and expensive effort on the order of $20 trillian dollars by the end of the century. However, not commiting to this goal will result in far more dramatic changes in weather incluing devasting drought, fatal sommer temperatures, famine, migrations, disease, sea level rise enough to make many coastal cities uninhabitable and lead to costs on the order of 10 times or more $20 trillian dollars. Or it simply will leave us with temperatures permanently rising and nothing that we can do about it. The ultimate shape of the curve will depend on future emissions and can be roughtly divided into four categories: 1. The temperature of the earth rises in proportion to our emissions, which are increasing. Is a serious problem. How serious depends on our emissions. 2. The temperare rises more rapidly than our emissions. This would be a calamity. 3. The rate of rise of the temperature increases with time. This would be at more than a calamity 4. The rate of rise of the rate of rise increases with time. This would be an exponential increase and would represent a situation where we have faild to do what was needed and the inhabital regions of the earth would be small or there would be none at all and we would have lost the earth as a place for human habitation.