The IPCC Report on Climate Change

On Monday, the Intergovernmental Panel on Climate Change (IPCC) released its highly anticipated Special Report on Global Warming of 1.5°C. The sixth of its kind and the product of eight years of collaboration between hundreds of experts, the report presents a damning conclusion: humans are categorically the cause of climate change, and some of these changes are now irreversible.

What is interesting (read: disheartening but not surprising) about the findings is that for the first time in history, the IPCC report is unequivocally holding humanity responsible for global warming (EarthSky, 2021). It found that in 2017, warming caused specifically by human activities have already reached about 1°C above pre-industrial levels, i.e. between the years 1850–1900 (while in principal it should be any time period before the start of the industrial revolution in the mid-1700s, the report explains that the chosen time period was the earliest whereby near-global climate observations were made).

The report also estimates that current temperate trends would mean that human-driven global warming could very well reach 1.5°C by 2040. This makes the ambitious goal set in the 2015 Paris Agreement to keep global temperatures from rising more than 1.5°C virtually impossible (Fortune, 2021; Business Insider, 2021).

Source: The Guardian (2021); IPCC (2021)

Still, there is some hope, even if it is just a sliver. The report explicitly states that limiting global warming to 1.5°C versus 2°C would generally give nature and humans a better chance of adapting to climatic changes, largely by reducing the risks and impacts associated with increased global temperature, including inter alia droughts, heat waves, sea level rise, terrestrial and marine biodiversity loss, food security, and water supply. However, according to co-ordinating lead author and University Chile’s Maisa Rojas, the catch is that “unless there are immediate, rapid and large-scale reductions of all greenhouse gases, limiting global warming to 1.5°C will be beyond reach” (Nature, 2021).

IPCC (2021): “Five integrative reasons for concern (RFCs) provide a framework for summarizing key impacts and risks across sectors and regions, and were introduced in the IPCC Third Assessment Report. RFCs illustrate the implications of global warming for people, economies and ecosystems. Impacts and/or risks for each RFC are based on assessment of the new literature that has appeared. As in [the IPCC 5th Assessment Report], this literature was used to make expert judgments to assess the levels of global warming at which levels of impact and/or risk are undetectable, moderate, high or very high. The selection of impacts and risks to natural, managed and human systems in the lower panel is illustrative and is not intended to be fully comprehensive.”

Ultimately, however, there is very little good news contained in the nearly 4,000 paged-assessment report—it paints a vivid picture of the severe adverse effects rising global temperature have caused—and will continue to cause—the planet, with UN Secretary-General António Guterres describing the report as essentially a “code red for humanity.” To drive the final nail in the coffin, as lead author and Imperial College London’s Joerji Rogelj states, this is likely the last report from the IPCC while there is time for the earth to stay below 1.5°C (The Guardian, 2021).