The latest IPCC climate science report and a call to action
August 16, 2021 | Charles Lin
Image by Gerd Altmann from Pixabay
Latest IPCC science climate report is a “code red for humanity”
The IPCC (Intergovernmental Panel on Climate Change) report, released on August 9, 2021, states it is beyond any reasonable doubt greenhouse gas emissions due to human activities have caused the planet to warm, the most categorical attribution to date by IPCC of global warming to human activities. The added certainty is a result of more observational data, better scientific understanding, and improved computer climate models over the past decade.
The report involved the participation of 234 scientists as authors from 66 countries, who reviewed and assessed over 14,000 cited references. IPCC reports are drafted and reviewed in several stages to ensure scientific objectivity and transparency. Scientists from Environment and Climate Change Canada (ECCC) have contributed as part of international teams to the current and earlier reports. As a former senior administrator responsible for climate science in ECCC and a member of Canadian delegations to previous international IPCC meetings, I can attest to the rigour of the review and assessment process.
In a press release, the UN Secretary General calls the latest IPCC climate science report a “code red for humanity”, and urges a step up of our efforts to limit global warming.
We summarize the key findings of the report, with a focus on heat extremes.
1. Our Earth will get warmer
Global warming will continue for the next several decades under all future emission scenarios examined by IPCC, as we have loaded the atmosphere with so much greenhouse gas with our past and current emissions. Global warming is already contributing to weather and climate extremes worldwide, including heat waves, heavy precipitation, droughts, and tropical hurricanes.
2. We can expect more heat extremes
Heat extremes, such as the recent record-smashing heat wave in British Columbia and Alberta, are expected to become more frequent and intense as global warming continues.
Let’s look at how the frequency of such heat waves would change in a warming world. The diagram below shows a once-in-a-decade heat wave in a pre-global warming world with no human greenhouse gas emissions has become almost 3 times more likely in today’s world with 1C warming. With another 0.5C warming to a 1.5C world, it is expected to occur 4 times more frequently.
3. Beyond hotter temperatures, we can expect other impacts
Climate change is bringing different changes in different parts of the world, and these changes will increase with further warming. Examples include:
- More intense rainfall and flooding, as well as more intense droughts;
- Continued sea level rise in coastal areas, contributing to more coastal flooding of low-lying areas and coastal erosion;
- Melting of glaciers and ice sheets, loss of seasonal snow cover, and loss of Arctic sea ice;
- Warming and acidification of the oceans, with impacts on ocean ecosystems and the people who rely on them;
- Cities, where large populations are concentrated, will be impacted through heat waves, flooding from heavy rainfall and sea level rise in coastal cities.
What can we do?
The short answer is a lot. Just as every ton of greenhouse gas emission contributes to global warming, every ton avoided achieves the opposite. The IPCC report examined different emission scenarios to 2050, and concluded we can still limit warming to about 1.5C, through strong, rapid and sustained reductions in greenhouse gas emissions starting now. There is something we all can do to contribute to this effort.
As consumers, we can make climate-friendly choices, such as
- reduce energy usage in our homes,
- reduce food waste and consume less meat,
- drive less or switch to an electric vehicle,
- influence our friends on climate-friendly actions.
As citizens, we can
- help elect politicians who know about climate issues and are prepared to act,
- lobby governments at the municipal, provincial and federal levels,
- exercise our civic duty to join lobbying groups in our cities for green initiatives,
- participate at grass root community groups and volunteer organizations.
The opportunities are plentiful and the need is real.
How impactnetzero.ca is doing its part
As we grow our website, we will provide more tools and tips to help facilitate the transition to a low-carbon lifestyle and economy, identify partner organizations that can help in this transition, and relate inspiring stories from consumers and citizens.
Appendix: IPCC resources and media coverage of the IPCC report
Charles is a retired atmospheric scientist based in Toronto. He stays busy as founder and lead of ImpactNetZero, keeping healthy in mind and body, and reading stories to his two grandchildren.