Meeting the temperature targets of the 2015 Paris Agreement will require massive reductions in fossil fuel consumption and unprecedented changes in all aspects of society, according to IPCC reports.
Earth is hotter than it will be in 125,000 years, but deadly heatwaves, storms and floods, compounded by global warming, could be a foretaste as fossil fuels warming the planet threaten a “livable” future.
That concludes the United Nations Intergovernmental Panel on Climate Change (IPCC), which launched a week-long meeting to distill six landmark reports totaling 10,000 pages produced by more than 1,000 scientists over the past six years.
Here are some of the key takeaways from these reports:
1.5C or 2C?
The 2015 Paris Agreement called for limiting global warming to well below 2 degrees Celsius (3.6 degrees Fahrenheit) compared to late 19th-century levels.
However, a landmark 2018 IPCC report left no doubt: only the treaty’s more ambitious target limit of 1.5°C (2.7°F) could ensure a climate-proof world. However, the report warns that achieving this goal will require “unprecedented changes in all aspects of society”.
Greenhouse gas emissions need to fall by 43 percent by 2030 — and 84 percent by mid-century — to stay below the threshold. Nonetheless, emissions continued to rise. The world is likely to surpass 1.5 degrees, albeit temporarily.
Every fraction of a degree counts. With a warming of 1.5 °C, 14 percent of terrestrial species are threatened with extinction. If temperatures rise 2°C, 99 percent of warm-water coral reefs – home to a quarter of marine life – will die and staple foods will decline.
The IPCC reports emphasize as never before the danger of “tipping points” – temperature thresholds in the climate system that, once exceeded, could lead to catastrophic and irreversible changes.
The Amazon Basin, for example, is already changing from a tropical forest to a savannah.
Warming of between 1.5°C and 2°C could depress Arctic Sea ice, methane-laden permafrost, and ice sheets with enough frozen water to lift the oceans a dozen meters past points of no return.
avalanche of suffering
The IPCC’s 2022 Impact Report – dubbed the “Atlas of Human Suffering” by UN chief Antonio Guterres – cataloged the enormous challenges facing humanity.
Between 3.3 and 3.6 billion people are “highly vulnerable” to the effects of global warming, including deadly heat waves, droughts, water shortages and disease-carrying mosquitoes and ticks.
Climate change has negatively impacted physical health worldwide and mental health in regions where data are available.
Annually through 2050, many flood-prone coastal cities and small island nations will be hit by weather catastrophes that used to happen once a century.
These and other impacts will only worsen, disproportionately harming the most vulnerable populations, including indigenous peoples.
“The accumulated scientific evidence is unequivocal: climate change is a threat to human well-being and the health of the planet,” said last year’s IPCC impact report.
Further delays in reducing carbon pollution and preparing for impacts already planned “will miss a short and rapidly closing window of opportunity to ensure a livable and sustainable future for all”.
ecosystems on the fringes
Fortunately, forests, plants and soil absorb and store almost a third of all man-made emissions. But the intensive exploitation of these natural resources also produces CO2, methane and nitrous oxide, which warms the planet. Agriculture uses 70 percent of the earth’s freshwater supplies.
The oceans have kept the planet livable by absorbing a quarter of man-made CO2 and absorbing more than 90 percent of the excess heat generated by greenhouse gases.
But this has come at a price: the seas have become more acidic, potentially eroding their ability to absorb CO2, and warmer surface waters have increased the power and range of deadly tropical storms.
Fossil fuels – it’s now or never
All pathways leading to a livable world “entail rapid and profound, and in most cases immediate, reductions in greenhouse gas emissions across all sectors,” including transport, agriculture, energy and cities, the IPCC concluded.
Meeting the Paris temperature targets will require a massive reduction in fossil fuel consumption, the IPCC said.
Coal-fired power plants that don’t use carbon capture technology to siphon off CO2 pollution will have to shrink by 70 to 90 percent within eight years. By 2050, the world must be carbon neutral, offsetting any remaining emissions by removing them from the atmosphere.
The world also needs to deal with methane (CH4), the IPCC warns. The second most important air pollutant after CO2 comes from leaks from fossil fuel production and agriculture, as well as from natural sources such as wetlands.
Methane levels are the highest in at least two million years.
The good news, the IPCC pointed out, is that alternatives to planet-warming fuels have become significantly cheaper. From 2010 to 2019, the unit cost of solar power fell by 85 percent, while the cost of wind power fell by 55 percent.
“It’s now or never if we want to limit global warming to 1.5°C,” said Jim Skea, a professor at Imperial College London and co-chair of the working group behind last year’s emissions reduction report.