(ORDO NEWS) — As researchers warn that limiting global warming to 1.5°C is quickly slipping out of our control, we know it will take a tremendous amount of effort to achieve this goal. But the scale of the emissions reductions needed is something we have already achieved – quite recently and quite by accident.
In 2020, global carbon dioxide (CO2) emissions fell by 6.3%, or about 2,200 metric tons (MtCO2), according to a new study published in the journal Nature Geoscience.
This reduction “is the largest absolute annual reduction in emissions, more than the reduction in emissions during the 2009 financial crisis (380 MtCO2) and even more than the reduction reconstructed at the end of World War II (814 MtCO2)”, writes the scientist in his paper. in Earth Systems from Tsinghua University Zhu Liu and colleagues.
But if we purposefully and controlledly made equivalent changes, then it is technically possible to achieve such emission reductions, and with much less negative consequences.
For example, the researchers found that the biggest driver of emissions reductions, accounting for almost a third of the decline, was the massive reduction in land transport – cars and trucks.
If, instead of shutting down ground transportation, we switched to renewable energy sources, we could achieve significant emission reductions without devastating consequences.
“This is a great demonstration that reducing emissions is possible, you just have to choose how we do it,” Nerili Abram, an Australian National University climate scientist who was not involved in the study, told the Australian Broadcasting Corporation.
“It’s not just that individuals are doing everything they can to cut back on travel – that sort of thing is not the solution. We need a planned transition across society to make the necessary changes.”
It will be an exorbitant effort, but the benefits will be enormous.
Limiting warming to 1.5°C would reduce human risks by about 40 percent compared to a 2°C scenario and up to 85 percent compared to a 3.66°C scenario, according to another study published this week in the journal Climatic Change.
University of East Anglia environmental scientist Rachel Warren and her colleagues used 21 types of climate models to account for water scarcity, heat stress, disease, flooding, drought and economic impacts.
They concluded that for each level of warming, hundreds of millions of additional people would be exposed to severe drought. But sticking to 1.5°C could reduce the global economic impact by 20% compared to a future 2°C, and even reduce the number of people exposed to malaria and dengue by 10%.
Since the lockdown, CO2 emissions have returned to 2019 levels, Liu and colleagues report. They suggest that post-pandemic recovery stimulus packages be geared towards mitigation strategies, but note that funding for such support continues to be dominated by fossil fuel investment.
These are the kinds of systemic problems that need to change in order to achieve long-term results, and these changes are already happening.
Unfortunately, a temperature rise of 2 degrees Celsius would cost life on Earth dearly – “in waves of irreversible extinctions and long-term damage to tens of thousands of species,” University of Cape Town ecologist Joanne Bentley and her colleagues write in The Conversation.
In their new study, they are trying to understand the extent of the damage this will cause to the ecosystems we depend on.
“An attempt to stop the rise in temperature is not an abstract attempt to bend the curves on the graph: it is a fight for a planet suitable for life.”
Even if the 1.5°C target is elusive, every fraction of a degree of warming matters. The 1.5°C goal has always been just to give you something tangible to aim for, it’s not a magical scientific number.
What’s more, we’ve already avoided some of the worst-case scenarios we’ve been heading towards, and researchers agree that we have every chance of limiting warming to below 2°C.
“If we get to 1.6°C, that’s better than 1.7°C; if we get to 1.7°C, that’s much better than 2°C. If we get to 2°C , it will be much better than what we were heading for 20 years ago – 5 °C,” climatologist Kathryn Hayhow from Texas Tech University told New Scientist in an interview.
“Every piece of warming counts. Every year counts, every choice counts, every action counts.”
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