Earth Today | World set to exceed warming of 1.5 degrees Celsius

EVEN WITH years-long global negotiations, public education and awareness efforts, as well as individual and country-level lobbying, the world appears set, at least temporarily, to surpass global warming of more than 1.5 degrees Celsius above pre-industrial levels within the next few years.

And why? Because international actions to cut greenhouse gas emissions from the human consumption of fossil fuels, including oil, coal and gas, which fuel the warming of the planet, have not been fast enough to avoid it. This is according to a new report published by the United Nations Environment Programme (UNEP).

The report, titled Limiting overshoot: Navigating exceedance of 1.5 degrees Celsius and pathways towards return, has warned that the exceedance of 1.5 is neither safe nor acceptable.

“ There are no benign scenarios with global temperature rise above this level,” it cautioned.

“ Risks and impacts include faster sea-level rise, a higher likelihood of collapse of ecosystems such as coral reefs, more extreme heat and wildfires, and profound changes to the cryosphere (ice sheets, sea ice, glaciers, permafrost and snow). For example, glaciers could lose more than a quarter of their mass by 2100, which could raise sea levels by 9 to 12.5` cm (for warming up to/less than +3 degrees Celsius) and permanently alter water availability in many places,” it added.

The report also said that there exists a “ higher risk of irreversible tipping points to global systems such as the West Antarctic and Greenland ice sheets, the Atlantic Meridional Overturning Circulation (AMOC) and the Amazon rainforest — which would reshape the world forever”.

The harm to people and planet, it noted, is clear, especially in small island developing states (SIDS).

“ While there are uncertainties around the timings and strength of these impacts and tipping points, it is clear they will harm people, societies and economies, particularly in SIDS and low-lying cities, some of which face partial or complete submersion,” the UNEP report revealed.

“ Food security and water supplies will be hit — for example, projections indicate declines of up to 14 per cent in global food production by 2050 in the absence of effective adaptation. More frequent and intense heatwaves, more nutrition-related diseases and greater risks of pathogen spillover will increase illnesses and deaths,” it added.

Cities and infrastructure will be at increased risk from “stronger and longer heatwaves and flooding” while “warming oceans, declining oxygen levels and rising acidity will make it harder for marine life and the communities that depend on it to survive”.

“Higher energy demand, consumer costs, and insurance and financial system stress will pose risks to all nations,” the report said.

The reality, it insisted, is that the goal remains limiting long-term, average warming to 1.5 degrees Celsius, with overshoot requiring that the goal be approached now “from above, while simultaneously adapting to the impacts of climate change”.

“This means meeting and exceeding, not rescinding, existing commitments and concurrently delivering faster mitigation and adaptation,” the report explained.

“With unprecedented action it is possible to minimise and adapt to the impacts of exceedance and return to 1.5 degrees Celsius — which would keep options open to protect the poor and vulnerable, minimise harm to infrastructure and livelihoods, and support people and nature,” it added.

To get there, however, the world must get on an ‘overshoot, peak and decline’ pathway, which, the report said, “holds temperature rise to the lowest level possible, then brings it down by the end of the century, all while taking adaptation actions that reduce vulnerability to the current or expected impacts of climate change”.

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