Climate Change 2021: The Physical Science Basis

The Intergovernmental Panel on Climate Change (IPCC) is the United Nations body responsible for assessing the science related to climate change. The Sixth Report from IPCC Working Group 1 published in August 2021 paints a very sombre picture for the future. This report was commented on in a news item by the International Science Council (ISC) on behalf of its members, of which IUPAC is a founding member.

The report presents the latest advances in modelling and improved historical data to lead to the undeniable conclusion that the whole world is experiencing the effects of climate change and that this is due to human activities. The extreme weather events which have occurred in 2021 are not taken into account. The goal of the Paris Agreement is that global warming is held to well below 2 oC with respect to pre-industrial values and efforts should be pursued to limit warming to 1.5 ºC. All five emission scenarios considered in the IPCC report lead to warming greater than 1.5 ºC and three of the five have warming of 2 ºC or greater by 2041-2060. The curbing of greenhouse gas emissions, mainly carbon dioxide, reducing the carbon footprint, will improve the situation and could potentially reverse the temperature trend later in the century if decisive action is taken urgently now. Ambitious targets are required and implementation is needed immediately.

Chemistry, often referred to as the central science, is crucial in the battle against climate change. Ways of reducing consumption of energy in chemical reactions and processes, renewable fuels produced from sunlight with photocatalysts, reagent recycling and waste reduction, new and more efficient materials are all needed. IUPAC, as a worldwide resource for chemistry with over a thousand volunteer scientists who are experts in their fields of chemistry, from academia and industry, can and must make an important contribution to these questions.

Christopher Brett, IUPAC President commented: “This landmark report on climate shows the current state of the world and the need for decisive and incisive action. We strongly support the statement by the ISC and emphasise the important role that chemistry will play in addressing the challenges. This is in accordance with a vision for IUPAC to be a global resource for chemistry for the service of humankind and the world. We are already working on many of the topics which will be crucial and we offer our expertise in addressing these issues which must be carried out in collaboration between all scientists and society as a whole.”

IUPAC has worked for years in several fields related to the challenges of climate change and the environment, green chemistry for sustainable development and world needs. Before the Covid-19 crisis, it was already implementing an organisational drive to make much greater use of on-line meetings, thus reducing travel and decreasing our carbon footprint.

Examples of IUPAC projects that address the challenges associated with climate change are:

Evaluated Kinetic Data for Atmospheric Chemistry

Climate and Global Change: Observed Impacts on Planet Earth

Multi-scale Biogeochemical Processes in Soil Ecosystems: Critical Reactions and Resilience to Climate Changes

Assessment of the Contribution of IUPAC Projects to the Achievement of the United Nations Sustainable Development Goals

Visualizing and Understanding the Science of Climate Change

Systems Thinking in Chemistry Education

Systems Thinking in Chemistry for Sustainability: Toward 2030 and Beyond

Green and Sustainable Chemical Processes


Further details may be found on the IUPAC website.

About IPCC & the 6th Assessment Report
The IPCC is now in its sixth assessment cycle, in which the IPCC is producing the Sixth Assessment Report (AR6) with contributions by its three Working Groups and a Synthesis Report, three Special Reports, and a refinement to its latest Methodology Report. The Synthesis Report will be the last of the AR6 products, currently due for release in 2022.
See also Report Fact sheet (8-page PDF)


Featured image  (the cover of the report) is Changing by Alisa Singer
“As we witness our planet transforming around us we watch, listen, measure … respond.” – 2021 Alisa Singer.