Climate change is happening and appears to be accelerating. The signals are global temperature increases, rising sea levels, the reducing extent of Arctic Sea ice, more frequent and severe weather events and the growing rate of habitat destruction and species extinction. We know the increased rate of climate change results from anthropogenic emissions of carbon dioxide and other greenhouse gases. Under the auspices of the United Nations (UN) world governments agreed in Paris in 2015 to limit the global temperature increase to well below 2°C above pre-industrial levels and to pursue efforts to limit the rise to 1.5oC to avoid potentially catastrophic impacts on human existence. The 1.5oC target gained increasing focus at COP 26 in Glasgow.
The 2018 Intergovernmental Panel on Climate Change (IPCC) special report(1) on the impacts of global warming of 1.5 °C above pre-industrial levels included emissions pathways to achieve this target. To achieve a 1.5°C rise with a 50% probability the remaining carbon budget is 580GtCO2. For a 2°C rise with the same probability the carbon budget is 1500GtCO2. Except for 1.2% fall in 2016, global CO2 emissions have increased annually since 2010 and in 2019 global emissions were 38GtCO2/year(2). Continuing at this level the available budgets would be consumed in 15 years for a 1.5°C rise and 39 years for a 2°C rise. These emission levels are for CO2 alone, including CO2 from land use change, but do not include other GHGs of which methane is a significant contributor. The economic downturn due to the COVID-19 pandemic has reduced 2020 CO2 emissions by about 7% largely due to mobility restrictions though emissions of other GHGs have been less affected. There is uncertainty on how the recovery from the pandemic will impact longer term trends.
In summary the IPCC emissions pathways to limit warming to below 2°C require net zero CO2 emissions by around 2050 from a peak in the 2020 to 2030 period. These emissions targets also require action on other GHGs particularly methane and also require the deployment of negative emissions technologies. The current levels of national emissions reduction commitments fall well short of this target though encouragingly in 2020 some 126 countries covering 51 per cent of global GHG emissions now have net-zero goals that are formally adopted, announced or under consideration. COP 26 did little to improve this situation except for a limited agreement on methane emissions and an agreement to report revised commitments in 2022. It is vital that countries in planning their recovery from the pandemic take the opportunity to translate these commitments into strong near-term policies and actions to secure the required emission reductions.
The impact of changes to the climate will continue to increase the frequency and severity of extreme weather events leading to loss of life and damage to property and infrastructure. Consider for example the fire storms seen in Australia and in the USA, flooding events around the world and the melting of the glaciers and Arctic ice and most recently the massive tornado across the central USA. Flooding, drought and particularly rising sea levels impact poorer communities to a more significant extent and some countries for instance the Maldives and the Pacific Islands are at the limit of existence.
In Malaysia coastal erosion is threatening the living and livelihood of large populations on the East Coast, this includes the disappearance of beaches and landmass. Ultimately these events will result in a movement of people into inland areas away from where coastal catastrophes are occurring. This movement of people will continue as we see the threatened disappearance of coastal cities and towns caused by rising sea levels and may result in mass migrations the likes of which we have not seen since the second World War.
The technology to address these situations and limit global temperature rise exists today but it is not being deployed fast enough due to a lack of political will and because some of the big emitters are committed to raising the standard of living of their populations at the lowest cost. These issues require to be addressed at a global level and it is not clear that the mechanisms provided through COPs are conducive to delivering solutions in the timescale required.
Chemical engineers as systems specialists with techno-economic analysis skills and who understand scaling and scaling laws will be essential in tackling climate change. To be influential they will have to get involved in the political process.
(1) IPCC Report “Global Warming of 1.5°C” October 2018 (www.ipcc.ch/reports/)
(2) UNEP Emissions Gap Report 2020 (https://www.unep.org/emissions-gap-report-2020)