A new assessment by the United Nations Intergovernmental Panel on Climate Change (IPCC) concludes that the world community could slow and then reduce global emissions of greenhouse gases (GHGs) over the next several decades by exploiting cost-effective policies and current and emerging technologies.
Based on the most up-to-date, peer-reviewed literature on emissions modelling, economics, policies and technologies, the report reveals how governments, industry and the general public could together reduce the energy and carbon intensity of the global economy despite growing incomes and population levels, IPCC says.
"Climate change will touch every corner and every community on this planet but equally, overcoming climate change can touch on every facet of the global economy in a wealth of positive ways. Measures to reduce emissions can, in the main, be achieved at starkly low costs especially when compared with the costs of inaction. Indeed some, such as reducing emissions by 30 percent from buildings by 2020, actually contribute positively to GDP, says Executive Director Achim Steiner of the UN Environment Programme (UNEP) which, together with the World Meteorological Organization, established the IPCC.
According to "Climate Change 2007: Mitigation of Climate Change", without additional action by governments the emissions from the basket of six greenhouse gases covered by the Kyoto Protocol will rise by 25 percent to 90 percent by 2030 compared to 2000. (The six gases are carbon dioxide, methane, nitrous oxide, sulphur hexafluoride, PFCs and HFCs.) By adopting stronger climate change policies, however, governments could slow and reverse these emissions trends and ultimately stabilize the level of greenhouse gases remaining in the atmosphere. For example, stabilizing GHG levels at 445 – 490ppm (parts per million) – the most ambitious target that was assessed – would require global CO2 emissions to peak by 2015 and to fall to 50 - 85% of 2000 levels by 2050. This could limit global mean temperature increases to 2 – 2.4°C above pre-industrial levels.
Stabilizing GHG levels at 535 - 590ppm would require global CO2 emissions to peak by 2010 – 2030 and return to -30% to +5% of 2000 levels by around 2050. This could limit the temperature increase to 2.8-3.2°C. If emissions peak later, more warming can be expected. By way of comparison, the current (2005) level of GHGs is about 379ppm.
The report addresses ways of reducing emissions from key sectors, including energy, transportation and buildings.
Buildings
Approximately 30 percent of the projected baseline emissions in the residential and commercial sectors – the highest rate amongst all sectors studied by the IPCC – could be reduced by 2030 with a net economic benefit. Energy consumption and embodied energy in buildings can be cut through greater use of existing technologies such as passive solar design, high-efficiency lighting and appliances, highly efficient ventilation and cooling systems, solar water heaters, insulation materials and techniques, high-reflectivity building materials and multiple glazing. Government policies such as continuously updated appliance standards and building energy codes could further contribute.
By producing co-benefits and lower life-cycle costs, emissions cuts in the buildings sector could even have net economic benefits rather than costs. However, particular attention would have to be paid to removing the market barriers (such as lack of proper incentives and access to information) that have prevented many of the available technologies from being widely adopted, IPCC says.
The Energy Supply Sector
The IPCC concludes that no single economically and technologically feasible solution would on its own suffice for reducing GHG emissions from the energy sector. Instead, governments would need to promote a range of options.
For example, they could encourage natural gas over more carbon-intensive fossil fuels as well as mature renewable energy technologies such as large hydro, biomass combustion and geothermal. Other renewable sources include solar assisted air conditioning, wave power and nanotechnology solar cells, although they all still require more technological or commercial development. Yet another option could be carbon capture and storage technology; CCS involves capturing carbon dioxide before it can be emitted into the atmosphere, transporting it to a secure location, and isolating it from the atmosphere, for example by storing it in a geological formation.
Irrespective of climate change, over $20 trillion is expected to be invested in upgrading global energy infrastructure from now until 2030. The additional cost for altering these investments in order to reduce greenhouse gas emissions would range from negligible to an increase of 5 percent to 10 percent.
