Regional News of Thursday, 17 January 2013
Research shows that tiny black particles released into the atmosphere by burning fuels are far more powerful agents of global warming than had previously been estimated.
This is according to a study published by some of the world’s most prominent atmospheric scientists reported in the Journal of Geophysics issued on January 15 and made available to the Ghana News Agency on Wednesday.
It said the black carbon is a type of carbonaceous material with a unique combination of physical properties and its aerosol plays a unique and important role in Earth's climate system.
The study provides an evaluation of black-carbon climate forcing that is comprehensive in its inclusion of all known and relevant processes and that is quantitative in providing best estimates and uncertainties of the main forcing terms: direct solar absorption, influence on liquid, mixed-phase, and ice clouds, and deposition on snow and ice.
It says these effects were calculated with climate models, but when possible, they were evaluated with both microphysical measurements and field observations.
The study produces new estimate of black carbon’s heat-trapping power is about double the one made in the last major report by the United Nations’ Intergovernmental Panel on Climate Change, 2007.
It says if indirect warming effects of the particles were factored in, they might be trapping heat at almost three times the previous estimate rate.
It notes that the new calculation added urgency to efforts to curb the production of black carbon, which was released primarily by diesel engines in the industrialized world and by primitive cook stoves and kerosene lamps in poorer nations and natural phenomena like forest fires also produce it.
The study estimates that black carbon is the second most important human emission in terms of its climate-forcing in the present-day atmosphere; only carbon dioxide is estimated to have a greater forcing.
It says for a few of these sources, such as diesel engines and possibly residential bio fuels, warming is strong enough that eliminating all emissions from these sources would reduce net climate forcing.
It reiterates that the uncertainties in net climate forcing from black-carbon-rich sources are substantial, largely due to lack of knowledge about cloud interactions with both black carbon and co-emitted organic carbon.
The study says in prioritizing potential black-carbon mitigation actions, non-science factors, such as technical feasibility, costs, policy design and implementation feasibility play important roles.
It says the major sources of black carbon are presently in different stages with regard to the feasibility for near-term mitigation.
It notes that this assessment by evaluating the large number and complexity of the associated physical and radioactive processes in black-carbon climate forcing, sets a baseline from which to improve future climate forcing estimates.
The study reaches its conclusions after factoring in a new series of measurements about the amount of black carbon accumulating in the atmosphere and how much heat from the sun it absorbs.