With the global total of emissions likely to come in at around 52 gigatonnes this year, we’re already at the edge, according to new research
That number reveals humanity’s steady billion-tonne by billion-tonne march to the edge of the carbon cliff, beyond which scientists warn lies a fateful fall to catastrophic climate change.
To have a good chance of staying below two degrees C of warming, global emissions should be between 41 and 47 gigatonnes (Gt) by 2020, said Joeri Rogelj, a climate scientist at Switzerland’s Institute for Atmospheric and Climate Science in Zurich.
“Only when we see the annual global emissions total decline will we know we’re making the shift to climate protection,” Rogelj told IPS.
Making the shift to a future climate with less than 2C of warming is doable and not that expensive if total emissions peak in the next few years and fall into the 41-47 Gt “sweet spot” by 2020, Rogelj and colleagues show in their detailed analysis published Sunday in the journal Nature Climate Change.
The study is the first to comprehensively quantify the costs and risks of emissions surpassing critical thresholds by 2020.
This shift means 65 percent of existing coal power plants will have to be shut down in the next decade or two.
“There are enormous benefits if global emissions decline before 2020. Failure to do so will mean we will need to use more nuclear, massive amounts of bioenergy, large-scale carbon capture and storage,” he said.
The costs and social implications from deploying all this will be “huge”, he said.
“Delay is by far the riskier option,” Rogelj said, noting that failure to act now means those additional risks, costs and social disruption will land on the heads of the next generation.
“We’re deciding that the next generation will have to pay significantly higher costs because we’re not doing anything now.”
These climate-disrupting emissions are primarily carbon dioxide (CO2) from burning fossil fuels and deforestation. The global total also includes other greenhouse gases that are warming the planet such as methane, nitrous oxide, and a few other chemicals.
In 1990, global emissions were 38.2 Gt, and in recent years, they have been growing at a rate of three percent per year. This growth is despite commitments by industrialised countries to reduce their emissions.
In 2009, all industrialised countries, including the United States, made emission reduction pledges under the Copenhagen Accord. However, even if countries reach their Copenhagen targets, global emissions will be about 55 Gt in 2020, the study estimates.
Staying below two degrees C is still feasible, but it will be far more expensive and difficult, imposing an additional cost burden amounting to trillions of dollars over 2020 to 2050.
Earlier this month, during the annual U.N. climate conference in Doha, governments declined to increase their emission cut targets. Citing economic difficulties, countries like the U.S. and those in the European Union looked to a new global climate treaty that would not make additional emission reductions until 2020.
Despite the urgent need to reduce emissions, the fossil fuel industry received a record 523 billion dollars in public subsidies in 2011, 30 percent more than the previous year, according to the International Energy Agency.
“Lots of actions at the local and national level are needed to bring emissions down over the next few years,” said energy researcher David McCollum of the International Institute for Applied Systems Analysis (IIASA), in Laxenburg, Austria.
Waiting until 2020 before emissions decline means millions of hectares of land will be needed to produce biofuel, billions of dollars invested in new nuclear power plants, and new technologies like carbon capture and storage must not only work but be effective on a large scale, McCollum told IPS.
“At 44Gt (in 2020) we can choose the most cost-effective reduction options. Above 55Gt, we need everything and they’d all better work,” he said.
The authors of the study acknowledge these numbers might be too optimistic because current climate models cannot incorporate emissions from melting permafrost and other natural sources of greenhouse gases that might result from increasing temperatures.
Staying below two degrees is not a matter of science or technology. It will be determined by political and social decisions to take the necessary steps to shift to low-carbon living, said McCollum.
And, in that regard, the choices made before 2020 are critical, both he and Rogelj conclude.
- Global warming: The longer we wait, the harder it gets (summitcountyvoice.com)
- Climate Change Tipping Point: Research Shows That Emission Reductions Must Occur by 2020 (blogs.smithsonianmag.com)
- Wales News: Carbon dioxide levels in Wales rise faster than many parts of UK (walesonline.co.uk)
- Nature Climate Change: Action by 2020 key for limiting climate change (prn.fm)
- Why the Doha climate conference was a success | Connie Hedegaard (guardian.co.uk)
- Imports drive up UK carbon emissions (guardian.co.uk)
- Kyoto Protocol fails: get ready for a hotter world (theconversation.edu.au)
- UN report warns of widening climate gap (thehindu.com)
- China and US hold the key to a new global climate deal (guardian.co.uk)
From The Independent
A lack of international will means the chances of bringing climate change under control may already be “slipping out of reach”, scientists have warned.
A study by the Swiss science university ETH Zurich shows that without an early and steep cut in greenhouse gas emissions, global temperatures are not “likely” to remain less than 2C higher than pre-industrial levels. The 2C target, which experts say is needed to avert dangerous climate change, was agreed by the UN climate conference in Copenhagen in 2009.
But countries that signed up to the Copenhagen Accord have yet to commit to measures far-reaching enough to meet it, according to experts.
A voluntary agreement hammered out in the dying hours of last December’s UN climate talks in the Danish capital is said to fall well short of the cuts required.
The new report, published today in the journal Nature Climate Change, sounds a further loud warning that time is running out. It suggests that for a “likely” chance (more than 66%) of holding warming below 2C by the end of this century, emissions must peak before 2020.
Emission levels will also have to drop drastically to around 44 billion tonnes in 2020, and then keep falling. By 2050, they will need to be well below 1990 levels at around 20 billion tonnes, says the research.
This is an ambitious goal. Last year’s emission levels were estimated to be 48 billion tonnes. If no action is taken to reduce global emissions, experts fear they could grow to 56 billion tonnes in 2020.
Authors of the new study, led by Dr Joeri Rogeli, from the Swiss science university ETH Zurich, wrote: “Without a firm commitment to put in place the mechanisms to enable an early global emissions peak followed by steep reductions thereafter, there are significant risks that the 2C target, endorsed by so many nations, is already slipping out of reach.”
The scientists base their conclusions on a comprehensive risk analysis of emission scenarios.
The research takes into account results from a number of previous integrated assessment models on climate change. These incorporate data from a range of different disciplines and are designed to inform policy.
Three pathways were identified that could result in a “very likely”, or more than 90%, chance of not exceeding the 2C threshold.
All involved a peak during this decade, high post-peak reduction rates, net negative emissions, and heavy use of renewable energy sources and carbon capture technology.
Scenarios showing peak emissions around 2030 were likely to keep warming below 3C, but would miss the 2C target. Another study published in Nature Climate Change suggests that if greenhouse gas emissions continue to rise, the 2C threshold could be crossed between 2040 and 2060. This is well within the lifetime of many people alive today.
The research examines the idea of looking at climate change projections from a different angle, shifting the emphasis from “what” to “when”.
Lead author Dr Manoj Joshi, from the University of Reading, said: “It is not just about avoiding potentially dangerous climate change, but also about buying time for adaptation.
“This approach to communicating the impacts and uncertainties of climate change draws attention to rates of change rather than just the change itself. It complements existing methods, and should be employed more widely.”
- Climate change mitigation ‘out of reach’ (chimalaya.org)
- Two degree climate target slipping away: paper (theage.com.au)
- Global warming: California may list pikas as endangered (summitcountyvoice.com)
- Bleak Prospects for Avoiding Dangerous Global Warming (news.sciencemag.org)
- NYTimes: Local measures won’t solve climate problem (junkscience.com)
- Climate change: now is not the time to renege on green pledges (chimalaya.org)
- You: Population growth tests Africa’s expanding cities (ourworld.unu.edu)
- Climate change : Study finds no grounds for climate sceptics’ concerns (environmentaleducationuk.wordpress.com)
- Have the skeptics been debunked? (junkscience.com)
- On the Church of Climate Change (cao2.wordpress.com)