German researchers this week dismissed the greenhouse gas emissions cuts agreed by the summit of world leaders in December as “paltry”. Joeri Rogelj, Malte Meinshausen and colleagues predict that the Copenhagen Accord will in fact lead to a 10-20% overall increase in emissions by 2020. Writing in the prestigious journal Nature on Thursday, the Potsdam Institute of Climate Impact Research scientists also point out two loopholes that could allow higher emissions. “The Copenhagen Accord has a stated aim of keeping global warming to below 2°C, and reviewing a 1.5°C goal by 2015,” Rogelj and Meinshausen write. “Unfortunately, the national emissions-reduction pledges accompanying this document are insufficient to meet this objective.”
They note that the Copenhagen Accord contained tables of national pledges that were supposed to be filled in by 1 February, however around 20% of global emissions are yet to be entered. Those commitments actually made by nearly all developed countries bar Japan and Norway show a similar lack of urgency. “It is amazing how unambitious these pledges are,” the scientists write.
In their most optimistic scenario, Rogelj and Meinshausen’s team estimate that the present pledges are likely to lead to global emissions equivalent to 47.9 billion tonnes of CO2 per year by 2020. However the loopholes that they see allow countries to save up emissions allowances and record the amount of CO2 removed through land management – such as planting forests – as credits for later use. If these are exploited, emissions by 2020 could rise to 53.6 billion tonnes.
While some researchers say that 48 billion tonnes is on the right track, the Potsdam scientists argue that this level would require “extremely ambitious rates of emissions reductions” after 2020. “Such pathways lull decision-makers into a false sense of security that emissions trends can continue upwards for the next decade without any ramifications,” they write. “The only way to achieve the 2 °C limit without betting on extreme reduction rates is to increase cuts before and by 2020.” This is especially important, because goals on long-term emissions cuts were removed from the final draft of the Copenhagen Accord. Consequently Rogelj and Meinshausen say that it’s vital that countries agree more serious cuts either during this year’s negotiations in Mexico, or in further meetings next year at the latest. “It is imperative that they do so,” the scientists write. “The prospects for limiting global warming to 2 °C are in dire peril.”
Meanwhile, also on Thursday, the US National Research Council warned that increasing concentrations of CO2 in the atmosphere are changing ocean chemistry at an unprecedented rate. At the request of Congress, it gathered together 33 leading experts on the subject to summarise what’s happening in our seas chemically, and even more scientists to review that summary. “The ocean absorbs a significant portion of CO2 emissions from human activities, equivalent to about one-third of the total emissions for the past 200 years from fossil fuel combustion, cement production and land use change,” the report explains.
The CO2 taken up by the ocean makes it more acidic, and the extent of acidification seen since the industrial revolution is basically unmatched. “The rate of this change exceeds any known change in ocean chemistry for at least 800,000 years,” the report explains. “While the ultimate consequences are still unknown, there is a risk of ecosystem changes that threaten coral reefs, fisheries, protected species, and other natural resources of value to society.” You can read the full report for free and get the same quality of explanation Congress is getting here.