A sober warning came overnight Monday from climate scientists that immediate action is needed to keep temperature rises within 1.5°C of pre-industrial averages. It came with advice for the buildings sector on how to mitigate and adapt to a warmer world.
Climate scientists issued their “final warning” on the urgent need to act now on reducing greenhouse emissions to prevent dangerous and irreversible climate change in the UN Intergovernmental Panel on Climate Change’s latest assessment report, issued overnight in Geneva.
The stark warning, which UN secretary-general Antonio Guterres described as a “clarion call to massively fast-track climate efforts by every country, and every sector, and on every time frame.
“Our world needs climate action on all fronts, everything, everywhere, all at once”
Monday’s “AR6 Synthesis Report” is the final volume in the IPCC’s Sixth Assessment cycle, and likely the last for this decade.
It is based on the content of three earlier reports: WGI – The Physical Science Bias, WGII – Impacts, Adaptation and Vulnerability and WGIII – Mitigation of Climate Change.
Global temperatures rose an average of 1.09°C above 1900 levels in the past decade, with 79 per cent of the increase coming from the energy, industry, transport and building sectors, the report stated. The highest 10 per cent of households contribute up to 45 per cent of global household consumption-based emissions, with the bottom 10 per cent contributing just 10-15 per cent.
The report paints a sobering picture of human-induced climate change, including 3.7mm annual sea level rises since 2016, increases in frequencies of concurrent heatwaves and droughts and millions of people exposed to food security and reduced water security across communities in Africa, Asia, South America and Australia.
Meanwhile, damage and irreversible loss to terrestrial, freshwater cryospheric and open ocean ecosystems has been chartered, along with the loss of hundreds of species due to increased numbers of severe heatwaves.
Gutierrez maintains that the 1.5°C limit is achievable, but that it will take a “quantum leap” in climate action, with atmospheric concentrations of CO2 at their highest level in at least two million years.
The target is achievable if countries undertake ‘deep global GHG emissions reductions this decade’
AR6 Synthesis Report
If countries stick to their current Nationally Determined Contributions, they will overshoot modelled pathways to constrain warming to 1.5°C. band and lead to a median global warning of 2.8°C by 2100.
However, this target is achievable if countries undertake “deep global GHG emissions reductions this decade,” the report noted. GHG emissions reductions would need to peak before 2025 to keep temperature rises within 1.5°C.
We can slash emissions through the built environment
The report highlights demand-side solutions that can potentially reduce emissions in the buildings, land transport and food sectors by 40-70 per cent by 2050 compared to baseline scenarios. In the buildings sector, emissions reductions of up to 66 per cent are possible through energy efficient buildings, lighting and appliances, and onsite renewables complemented by renewable fuels for transport, public transport and cycling, and efficient shipping and aviation.
Time for the 15-minute city and better land use planning
Further emissions reductions, adaptation and mitigation is possible in land-use planning, design of urban areas and infrastructure through measures such as co-locating jobs and infrastructure (think 15-minute cities), public transport and active mobility and efficient retrofit and adaptive reuse of buildings that involves reducing material consumption and electrification, the report noted.
The potential for green and blue infrastructure to support carbon uptake and storage and reduce the risk of adverse implications from heatwaves and flooding receives a special mention in the report.
The main risks Australia faces include irreversible loss of coral reefs, alpine species, of kelp forests, plus sea-level rises, an increase in severe fire weather days, collapse of forests in southern Australia and an increase in fatal heatwaves.
Australia is one of the most exposed to climate risk
“Australia is one of the most vulnerable developed countries to the impacts of climate change and we’ve seen the risks dramatically escalate over the past five years. We have much to lose and everything to gain by acting decisively to get emissions plummeting this critical decade,” former IPCC author and distinguished professor of biology at Macquarie University, and Climate Councillor, Professor Lesley Hughes said.