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By Daniel Kirby, Climate Progress
Drastic cuts in emissions are required over the next two decades if we are to avoid catastrophe from climate change, the scientific body overseeing U.N. research says in a new report.
“After around 2030, emissions must peak and start declining, mainly from economic sectors such as deforestation and shipping,” the Intergovernmental Panel on Climate Change concludes.
But the report “unfortunately” warns that “the governments, including those in the process of drafting (the) 2016-2030 climate action plans, must take the means of implementation more seriously than they are currently”.
Few areas will need greater reductions than emissions of heat-trapping carbon dioxide from power plants, buildings, vehicles, and industry.
“Since 2000, the pace of change in emissions per unit of gross domestic product has decelerated, but the rate of emissions increase has picked up in the last two years,” the report states.
This means we should expect increased levels of emissions in the coming decades, though perhaps at a slower rate. While overall emissions have continued to rise, the report notes, that has not been in line with global economic growth. And as economies grow, we can expect emissions to grow at around 2 percent a year.
“An economic slowdown would attenuate climate risks, but only for a time, with the overall trend over the period 2035–2050 still challenging,” the IPCC reports.
The chance that emissions will keep rising “even if all policies to help limit emissions are successfully implemented and scaled up to mid-century” is 20 percent, according to the report. And there’s only a 25 percent chance that levels of emissions will level off at that point.
“Levels of greenhouse gas emissions during the coming decades will determine whether we are able to keep temperature increases between 1.5°C and 2°C below pre-industrial levels, and whether we can avoid dangerous impacts,” the report reads. (On average, over 80 scientists (38.3 percent) from around the world reviewed the draft.)
An important component of slowing emissions is to keep a lid on the increase in coal use, despite its improving efficiency. The report warns that the growing use of coal, especially in China, “is a key challenge for emissions reduction.”
“Even assuming the best possible regulatory and pricing policies, which are currently not being implemented and that could possibly be made more effective, coal may not play a significant role in electricity generation until 2035 and a little after, depending on the energy mix, fuel mix, and the policy mix in China,” the report concludes.
Arguably the more profound challenge to climate action involves the increasing impact of melting sea ice.
“Sea ice cover is decreasing across the world but more sharply in the Arctic and will continue to decline for at least the next several decades,” the report states. “There are indications that average sea ice extent could fall between 39% and 60% below the level that prevailed at the end of the last interglacial period.”
While the melting of the polar icecap will most likely influence ice volume, impact is also being seen in the Northern Hemisphere. “There are indications that the two largest ice sheets in the world — the Greenland and West Antarctic ice sheets — are also undergoing long-term changes,” the report says.
While glaciers in Greenland are going “in both directions”, the West Antarctic ice sheet “is particularly vulnerable as ice loss and reduction of ice volume are projected to accelerate in the future, even if global warming slows down.”
“The current rate of sea level rise has been more than double the level experienced during the last interglacial period, between about 115,000 years ago and 120,000 years ago. There is substantial scientific uncertainty about future sea level rise, although little increase in sea level due to climate change is anticipated from global warming. There is general agreement that sea level rise associated with climate change is likely to exceed a metre by 2100,” the report warns.
In sum, the IPCC report provides a reasonable basis for seeking to cut emissions, to keep global warming to 1.5 degrees Celsius, and to avoid some of the worst impacts of climate change. But the report also warns us that politicians and bureaucrats have “no good options for mitigating climate change unless society acts together and enforces tough policies.”
Unfortunately, those actions and solutions will take time to implement, and will be expensive. It’s unlikely governments will be able to protect the world from catastrophe within the next two decades.
