A United Nation report says it’s still possible to restrict warming to below 1.5°C, but this requires substantial, sector-wide effort immediately. (Waldo Swiegers/Bloomberg via Getty Images)
Global temperatures may breach the 1.5°C global target without “immediate and deep emissions reductions” across the board, the Intergovernmental Panel on Climate Change (IPCC) has warned in its latest report.
The report is the third and final instalment of its current assessment cycle and looks at what humanity can do to limit and prevent human-caused emissions that cause global warming.
The authors emphasise that global greenhouse gas emissions must peak in less than three years and be slashed by 43% by 2030. At the same time, methane would need to be cut by about a third.
“That is an incredibly rapid rate of change,” Professor Harald Winkler of the University of Cape Town’s faculty of engineering and the built environment, told the Presidential Climate Commission this week.
“Even if we did those top reductions, we would still likely overshoot, we would exceed 1.5°C for some time but by the end of the century, the temperature levels might return to those levels,” he said. The world has already warmed by about 1.1°C since the pre-industrial era.
‘Now or never’
While the 2010-2019 average annual global greenhouse gas emissions were at their highest levels in human history, the rate of growth has slowed. And there is increasing evidence of climate action.
“We are at a crossroads,” IPCC chairperson Hoesung Lee said in a statement. “The decisions we make now can secure a liveable future. We have the tools and know-how required to limit warming.”
Net human-caused emissions have climbed in the past 12 years across all major sectors. “An increasing share of emissions can be attributed to urban areas. Emissions reductions in carbon dioxide from fossil fuels and industrial processes, due to improvements in energy intensity of GDP and carbon intensity of energy, have been less than emissions increases from rising global activity levels in industry, energy supply, transport, agriculture and buildings,” the report says.
Without a strengthening of policies beyond those implemented by the end of 2020, greenhouse gas emissions are projected to rise beyond 2025, leading to a median global warming of 3.2°C by 2100.
“It’s now or never, if we want to limit global warming to 1.5°C,” said Jim Skea, the co-chair of the working group behind the report. “Without immediate and deep emissions reductions across all sectors, it will be impossible.”
Climate change, he said, is the result of more than a century of unsustainable energy and land use, lifestyles and patterns of consumption and production.
Net zero
The report describes how the continued installation of “unabated” fossil fuel infrastructure will “lock-in” greenhouse gas emissions and how electricity systems powered mostly by renewables are becoming increasingly viable.
It moots the controversial large-scale deployment of carbon dioxide removal as “unavoidable” if the world is to reach net-zero greenhouse gas emissions.
There are options to at least halve emissions by 2030 in all sectors. Limiting warming will require major transitions in the energy sector, requiring a substantial reduction in fossil fuel use, widespread electrification, improved energy efficiency and use of alternative fuels such as hydrogen.
Since 2010, there have been sustained decreases of up to 85% in the costs of solar and wind energy, and batteries. “An increasing range of policies and laws have enhanced energy efficiency, reduced rates of deforestation and accelerated the deployment of renewable energy.”
Although use is increasing rapidly, low-carbon electricity generation levels and rates are “currently insufficient to meet stringent climate goals”, with the combined market share of solar PV and wind generation technologies still below 10%. “Global low-carbon electricity generation will have to reach 100% by 2050, which is challenged by the continuous global increase in electricity demand.”
Atmospheric carbon dioxide concentrations continued to rise in 2020 and emissions have already rebounded as lockdown policies are eased, said the report. “Economic recovery packages currently include support for fossil fuel industries … Global coal emissions may not have peaked yet, and a few countries and international development banks continue to fund and develop new coal capacity.”
Current pledges don’t go far enough
Transport emissions have remained roughly constant, growing at an average of 2% a year from 2010 to 2019 because of “the persistence of high travel demand, heavier vehicles, low efficiencies, and car-centric development … The full decarbonisation of e-vehicles requires that they are charged with zero-carbon electricity, and that car production, shipping, aviation and supply chains are decarbonised.”
Current national pledges under the 2015 Paris Agreement are insufficient to limit warming to 1.5°C with no or limited overshoot “and would require an abrupt acceleration of mitigation efforts after 2030 to likely limit warming to 2°C”.
The report says 10% of households with the highest per capita emissions contribute a “disproportionately large share of global household greenhouse gas emissions” — about 40%.
It says “choice architecture” can help end-users adopt, as relevant to consumers, culture and country contexts, “low greenhouse gas intensive options” such as balanced, sustainable healthy diets acknowledging nutritional needs; food waste reduction; adaptive heating and cooling choices for thermal comfort; integrated building renewable energy; and electric light-duty vehicles, and shifts to walking, cycling, shared pooled and public transit; sustainable consumption by intensive use of longer-lived repairable products.
“The report recognises that interventions like changes in infrastructure, in the types of technologies that people will use to fulfil their needs and behavioural changes can play a massive role in reducing global emissions,” Brett Cohen, an IPCC lead author and an honorary professor at the University of Cape Town, told a briefing this week. “Just the way that we present choices to people about their diets, the way they manage food waste and their energy choices can impact on our behaviours and therefore the emissions that arise from the demand element of society.”
Although the report explores relative emissions associated with plant-based diets versus animal protein-based diets, it “doesn’t necessarily suggest that we all have to transition to plant-based diets because we recognise that there are cultural aspects associated with it, and we recognise there are parts of the world where people are heavily dependant on animal-based proteins as part of their diets”, Cohen said.