When the world joined hands and agreed to sign the Paris Climate Agreement in 2015, they vowed to do everything in their capacity to limit the rise of global temperatures to “well below” 3.6 degrees Fahrenheit (2 degrees C) above pre-industrial levels, preferably at 2.7 degrees Fahrenheit (1.5 degrees C). While a majority of countries involved in that agreement has since taken drastic measures to mitigate anthropogenic global warming, it might have been a little too late. Global temperature has already increased by 1.1 degrees C, almost three-quarter of the preferred level. The consequences of are being felt in every corner of the world – an increase in extreme weather, the unprecedented rising of sea levels and the diminishing Arctic sea ice. Based on current levels of greenhouse gas emissions, the threshold of 1.5 degrees C might occur as early as 2030.
The report was issued on 8th October, 2018 by the UN Intergovernmental Panel on Climate Change (IPCC), which reviewed more than 6,000 scientific studies to arrive at the conclusion. The committee mentioned that even if the net carbon emission would reduce to zero at the very moment, the property of greenhouse gases to stay in the atmosphere would mean that global temperatures would continue to rise. Realistically, in order to keep warming around 1.5 degrees C, global net emissions of carbon dioxide should reduce by 45% from 2010 levels by 2030 and reach “net zero” around 2050. The amount of warming is ultimately determined by how long it takes to get to net zero.
If the emission level is not reduced to those levels, people must indulge in creative engineering solutions to ensure that temperature doesn’t rise to 1.5 degrees, including a greater reliance on techniques such as “carbon capture and storage”. In the planet’s history, volcanic activities have known to cool down the earth’s temperature – which has raised the possibility of inducing an artificial volcano that emits ash into the atmosphere. However, such solutions carry significant risks for sustainable development but could prove to be the last resort available.
Given the current political discourse, it might not be possible to limit global temperatures to rise by 1.5 degrees C. However, the IPCC report mentions that the effects of a 2 degree C rise are substantially more worrisome. The proportion of the global population exposed to water stress (difficulty obtaining fresh water) could be 50 % lower at 1.5 degrees than at 2 degrees. A 0.5-degree rise can result in a 10 cm of sea-level rise that could impact 10 million more people. At 2 degree C warming, we would lose 99% of our corals as compared to around 10% of them being saved at 1.5 degrees C. Insects are twice as likely to lose half their habitat with the change, and double the number of species will lose “half their geographic range”, if temperatures are allowed to reach 2 degrees C instead of 1.5.
The window on keeping global warming below 1.5 degrees C is closing rapidly and the current emissions pledges made by signatories to the Paris Agreement do not add up to us achieving that goal. While limiting global warming to 1.5 degrees C is “possible within the laws of chemistry and physics”, to do so would require unprecedented changes in energy, industry, buildings, transportation, and cities.