UN issues now-or-never alert on climate change: What it means for buildings

This week, the Intergovernmental Panel on Climate Change (IPCC), a consortium of top global scientists convened by the United Nations, released its latest report entitled, Climate Change 2022: Mitigation of Climate Change. Working Group III Contribution to the IPCC Sixth Assessment Report.

The report was finalized on April 4 during the 14th Session of Working Group III and 56th Session of the IPCC. Per IPCC, the Working Group III report provides an updated global assessment of climate change mitigation progress and pledges, and examines the sources of global emissions. The report also explains developments in emission reduction and mitigation efforts, while assessing the impact of national climate pledges in relation to long-term emissions goals.

As summarized by news coverage in the Guardian (UK), "The report on Monday was the third and final section of the IPCC’s latest comprehensive review of climate science, drawing on the work of thousands of scientists. IPCC reports take about seven years to compile, making this potentially the last warning before the world is set irrevocably on a path to climate breakdown...The world can still hope to stave off the worst ravages of climate breakdown but only through a 'now or never' dash to a low-carbon economy and society, scientists said in what is in effect a final warning for governments on the climate."

'Immediate and deep' cuts to global GHG emissions are required

During a press conference and in a press release, the IPCC laid out the report's salient points.

The IPCC stated that in 2010-2019, average annual global greenhouse gas (GHG) emissions were at their highest levels in human history, but that the rate of growth has slowed. However, the scientists said that "without immediate and deep emissions reductions across all sectors, limiting global warming to 1.5°C is beyond reach."

Based on IPCC-assessed scenarios, the new study found that limiting warming to 1.5 °C would require that global GHG emissions peak before 2025, and are reduced by 43% by 2030, with methane reduced by 34% by 2030. The report added that limiting warming to around 2°C would require that global GHG emissions peak before 2025, and and are reduced by 27% by 2030.

The IPCC also noted that within the reporting period it discerned "increased evidence of climate action," with some countries having achieved a steady decrease in emissions consistent with limiting warming to 2°C. The study also found that zero emissions targets have been adopted worldwide by at least 826 cities and 103 regions.

Focus on buildings

The Washington Post's coverage of the study observed that "emissions from buildings accounted for roughly 21 percent of greenhouse gases spewed into the atmosphere in 2019, according to the IPCC. That number includes indirect emissions from the power used for electricity and heat, as well as emissions from the use of steel and cement," added the reporting.

The Washington Post further noted that "decarbonizing the world’s buildings won’t happen quickly or easily, [but] widespread efforts to create more efficient and climate-conscious buildings could have profound impacts in helping the world reduce its carbon pollution. Some strategies [may] include better insulation, more efficient heating and cooling systems, powering buildings with more renewable energy, and using more sustainable construction materials."

Acknowledging that some zero energy and zero-carbon buildings already exist, the IPCC stated that it is possible for buildings to reach net zero emissions by 2050, but that action in this decade is critical to fully capture this potential -- and will involve retrofitting existing buildings and effective mitigation techniques in new buildings. The study noted that that such approaches require ambitious policy packages and financial incentives.

However, as noted by the New York Times' coverage of the study's release, "By contrast, current policies by governments are only expected to reduce global emissions by a few percentage points this decade. Last year, fossil fuel emissions worldwide rebounded to near-record highs after a brief dip as a result of the coronavirus pandemic," added the reporting.

As further quoted by the New York Times, “This is a climate emergency,” said United Nations Secretary General António Guterres. Guterres added that wealthy economies and corporations “are not just turning a blind eye; they are adding fuel to the flames. They are choking our planet, based on their vested interests and historic investments in fossil fuels, when cheaper, renewable solutions provide green jobs, energy security and greater price stability.”

The IPCC report stated that key options for existing, rapidly growing and new cities would include: better urban planning; electrification (low-emission energy); enhancing carbon uptake and storage via more green spaces, ponds, trees; and sustainable production and consumption of goods and services.

“We see examples of zero energy or zero-carbon buildings in almost all climates,” said IPCC Working Group III Co-Chair Jim Skea, who added, “Action in this decade is critical to capture the mitigation potential of buildings.”

A renewable energy crossroads

The new IPCC report emphasized that in some cases around the world, costs for renewables have fallen below those of fossil fuels, and that electricity systems in some countries and regions are already predominantly powered by renewables.

The IPCC found that, since 2010, there have been sustained decreases of up to 85% in the costs of solar and wind energy, and batteries. The research further found that an increasing range of policies and laws have already enhanced energy efficiency, reduced rates of deforestation and accelerated the deployment of renewable energy.

“Having the right policies, infrastructure and technology in place to enable changes to our lifestyles and behaviour can result in a 40-70% reduction in greenhouse gas emissions by 2050,” said IPCC Working Group III Co-Chair Priyadarshi Shukla. "This offers significant untapped potential. The evidence also shows that these lifestyle changes can improve our health and wellbeing.”

However, “it’s now or never, if we want to limit global warming to 1.5°C (2.7°F),” warned Skea. “Without immediate and deep emissions reductions across all sectors, it will be impossible.”

“We are at a crossroads,” agreed IPCC Chair Hoesung Lee, who concluded, "The decisions we make now can secure a livable future. We have the tools and know-how required to limit warming. I am encouraged by climate action being taken in many countries. There are policies, regulations and market instruments that are proving effective. If these are scaled up and applied more widely and equitably, they can support deep emissions reductions and stimulate innovation.”