Reducing climate gas emissions by 2020 to a level that could keep 21st century temperature rises under 2ºC is technologically and economically feasible, according to a new study from the UN Environment Programme (UNEP).
Moving faster towards renewable energy technologies, fuel-switching and better energy efficiency could deliver a large slice of the greenhouse gas cuts needed to reduce temperature increases.
Other measures include better public transport systems, more fuel-efficient vehicles, and changes to farming and waste disposal systems.
The report also identifies the need for stricter curbs on climate gases from aviation and shipping, which are deemed to be “international emissions” falling outside the scope of the Kyoto Protocol emission reduction treaty.
Together, greenhouse emissions from aircraft and ships would account for about 5 percent of carbon dioxide (CO2) emissions, or roughly 2.5 gigatons of carbon dioxide equivalent (GtCO2e) emissions, a year by 2020.
(Carbon dioxide equivalent units – CO2e – is a term used to standardise the measurement of a variety of climate gases such as methane and other chemical substances that contribute to the greenhouse warming effect.)
“Options for reducing emissions from aviation and shipping include improving fuel efficiency and using low-carbon fuels. For the shipping sector, another promising and simple option is to reduce ship speeds,” says the report, which has involved 55 scientists and experts from 28 scientific groups across 15 countries.
The “Bridging the Emissions Gap” report, released to coincide with the COP17 talks, provides the “clearest indicators yet that the world already has the solutions to avert damaging climate change”.
It presents policymakers with clear ideas on how to bridge the so-called “emissions gap” by 2020, which is now estimated to be at least 6 GtCO2e.
The term “emissions gap” refers to the shortfall between the emissions cuts UN climate scientists recommend are necessary, and what governments have pledged, to prevent world temperatures rising by an average of 2°C before the turn of the century.
The report also outlines far more pessimistic scenarios.
If the emission reduction commitments are not fully realised, then the gap could be about 12 GtCO2e.
“The annual UNEP Gap Report is a vital contribution to the global effort to address dangerous climate change,” said UN Secretary-General Ban Ki-moon.
“It shows that we have much to do, in terms of ambition and policy, but it also shows that the gap can be closed if we act now.”
Achim Steiner, executive director of UNEP and UN Under-Secretary-General, said: “This report puts into the hands of governments and policymakers vital information about their options if the world is to meet the climate change challenge.
“This year, countries will be able to begin their deliberations in Durban with all the key technological and economic scenarios at their fingertips that outline the gap between current ambition and scientific reality alongside the urgent bridges that can be built to span this emissions divide.”
Christiana Figueres, executive secretary of the UN Framework Convention on Climate Change, emphasised the need for increased action.
“This study again reminds us that efforts to address climate change are still insufficient,” she said.
“But it also shows that it is possible for governments to bridge the gap between what they have promised and what needs to be done to stay below a 2°C average global temperature rise.”
The full report by UNEP may be downloaded at www.unep.org/publications/ebooks/bridgingemissionsgap