More than 1.5°C, which is likely to happen in our lives, does not mean that someone should feel apathetic or paralyzed. What sense would that make? There is no magic switch that flips at 1.5°C or 1.7 or 2.3 or 2.8 or 3.4. These are all ultimately arbitrary thresholds. Going beyond one in no way diminishes the moral and political imperative to remain under the other. On the contrary, the need to mobilize against climate change only increases with each new increase in heat, as potential deployments become larger. In short, there is no “safe” level of global warming. Climate change is not something bad that could happen, it is something bad that happens. Global average temperatures have risen by about 1.3°C from pre-industrial levels and California and Australia are already burning. The IPCC report mentioned above is behind the much-cited idea that “we only have 11 years” to avoid catastrophic climate change (which, I suppose, is now “only 10 years”). This slogan stems from the report`s conclusion that global emissions must decrease by at least 50% by 2030 to limit the temperature rise to 1.5°C. The question of whether the Earth can remain within 1.5°C of warming raises two different questions. First, is it physically, technically and economically feasible to take into account the physics of the Earth system and the possible speeds of social change? Science shows that the answer is yes – although it will be very difficult and the best chances of success are in the past. The 2009 Copenhagen Accord mentions the long-term temperature goal of keeping global temperature increase “below 2 degrees Celsius” (UNFCCC 2010).
A year later, the parties to the UNFCCC adopted the Cancun Agreements, which “further recognized that significant reductions in global greenhouse gas emissions are necessary to keep the rise in global average temperature below 2°C above pre-industrial levels.” This is what the CAT calls the Cancun 2°C target. IPCC SR1.5 also assesses other pathways leading to higher levels of warming, including pathways that keep warming below 2°C with a 66% probability and do not return to 1.5°C. IPCC SR1.5 provides an assessment of these signalling pathways for comparison and consistency with mitigation pathways compatible at 1.5°C. The IPCC`s SR1.5 is also very clear about the increase in climate risks between 1.5°C and 2°C, which refers to the clause in the Paris Agreement LTTG, which recognises that warming remains well below 2°C and limits it to 1.5°C to significantly reduce the risks and impacts of climate change. It is not that progress has not been made on many major issues. Poverty and hunger have decreased worldwide. In the United States, politics has changed dramatically in recent years on issues such as LGBTQ marriage and drug policy. Things can change quickly. Scientists said crossing the 1.5°C threshold carries the risk of having much more severe impacts of climate change on humans, wildlife and ecosystems. Progress has been made on the targets. According to the latest update, released just before the fifth anniversary of the Paris Agreement, if all national governments meet their net-zero emissions targets for 2050, warming could be as low as 2.1°C by 2100, putting the Paris Agreement`s 1.5°C limit at a striking distance.
At the current rate, global temperatures would reach 1.5°C by 2040. The stylized trajectory of 1.5°C illustrated here includes emission reductions that start immediately and CO2 emissions that reach zero by 2055. In 2015, the Paris Agreement set the long-term goal of “keeping the global average temperature rise well below 2°C above pre-industrial levels and working to limit the temperature rise to 1.5°C above pre-industrial levels, recognizing that this would significantly reduce the risks and impacts of climate change.” Emissions have never fallen to 15% a year, let alone everywhere. And what terrestrial reason do we have to believe that emissions will decrease this year? Look around! The democratic world is in the grip of a populist authoritarian reaction that shows no sign that it will resolve itself in the foreseeable future. Oil and gas infrastructure is being built at breakneck speed; Hundreds of new coal-fired power plants are in the works. No country has even come close to implementing the policies needed to set an emissions trajectory towards 1.5°C. Many, including the United States and Brazil, are running the other way. .