Targets ad trust. These are at the heart of a tougher new global climate
pact possibly just weeks away.
The bigger the pledged emission cuts or reductions in growth in carbon dioxide
pollution, the greater the need to prove nations meet those targets and curb
the pace of climate change.
And proof of emission reductions over time will help unlock billions of dollars
in climate funds for poor nations.
The problem, though, is that it is not yet possible to independently monitor
a country’s greenhouse gas emissions, such as carbon dioxide from burning
fossil fuels or deforestation.
Which is why measurement, reporting and auditing of nations’ greenhouse
gas emissions is a key focus of marathon UN climate talks. The world body
hopes the negotiations will lead to agreement on a tougher climate pact from
2013 during a meeting in Copenhagen next months.
Rich nations are under pressure from the developing world to sign up to emissions
cuts of 25-40% below 1990 levels by 2020 and funnel billions in aid and green
technology to the poor.
Big developing nations are also under pressure to curb the pace of their emission
growth. China, India, Indonesia and Brazil are among the world’s top
carbon polluters.
Huge variability
Rich nations such as Australia and US have developed reliable reporting methods
on energy use and fossil fuel emissions, said Pep Canadell of the Global Carbon
Project. Accuracy for developing countries was often not as good.
Noaa runs a global network that tests air samples for a variety of greenhouse
gases to build a picture of how their concentrations change over time. Carbon
dioxide levels are approaching 390 parts per million (ppm) compared with around
280 ppm at the start of the Industrial Revolution.
If carbon dioxide rises to 450 ppm, the UN climate panel says, the planet
is likely to warm by at least 2 degrees Celsius.
Dozens of countries also send greenhouse gas measurement data to the World
Meteorological Agency’s World Data Centre for Greenhouse Gases. Such
measurements can give annual and seasonal pictures of carbon emissions.
But scientists say we are at least a decade or two away from a monitoring
system that can accurately reveal national and regional emissions from fossil
fuels or from deforestation and other land use changes.
A global network will also need to take into account the huge amount of carbon
dioxide produced and absorbed naturally via so-called sources and sinks.
Trees and oceans soak up carbon dioxide, while bring or rotting vegetation
can release it. Winds distribute the gas around the globe, and how this occurs
in still not fully understood and is only poorly simulated in complex computer
models.
And that is where the real puzzle begins.
Because carbon dioxide is shifted around by the atmosphere, scientists need
powerful computers to simulate the movement of air around the globe and to
crunch all the data from an army of carbon dioxide monitoring sites on the
ground, in the air, and in space.
More accurate measurement and models which, for example, could show how much
carbon dioxide is absorbed by forests and oceans, could give in vestors more
confidence when putting money into large carbon offset schemes.
