Changes

===Human Intervention===

===Human Intervention===

Liberal politicians have trumpeted the imposition of [[carbon cap]]s and carbon-trading, in order to control the carbon footprints of companies and people. Although carbon cap-and-trade schemes are being implemented to certain extents and with some measured success in New Zealand<ref>New Zealand Ministry for the Environment. "Emissions Trading Fast Facts." September, 2008. http://www.mfe.govt.nz/publications/climate/emissions-factsheets/index.html</ref><ref>New Zealand Ministry for the Environment. "Summary of the proposed changes to NZ-ETS. September 2009. http://www.mfe.govt.nz/publications/climate/emissions-trading-bulletin-11/index.html</ref> and in the European Union<ref>Parker, Larry. <i>Climate Change: The European Union's Emissions Trading System</i>. July 31, 2006. Congressional Research Service, Library of Congress. http://fpc.state.gov/documents/organization/70317.pdf</ref>, and a similar, successful program for [[sulfur dioxide]] and nitrogen oxides was implemented in the U.S. under President [[George H.W. Bush]] as an amendment to the [[Clean Air Act]]<ref>U.S. Environmental Protection Agency. "Acid Rain Program 2007 Progress Report." http://www.epa.gov/airmarkt/progress/arp07.html</ref>, a "carbon currency" in the U.S. still has many logistical hurdles and has the potential for abuse.<ref>[http://www.msnbc.msn.com/id/18180878/ MSNBC] Devil is in details of carbon cap system</ref>

Liberal politicians have trumpeted the imposition of [[carbon cap]]s and carbon-trading, in order to control the carbon footprints of companies and people. Although market-based carbon cap-and-trade schemes are being implemented to certain extents and with some measured success in New Zealand<ref>New Zealand Ministry for the Environment. "Emissions Trading Fast Facts." September, 2008. http://www.mfe.govt.nz/publications/climate/emissions-factsheets/index.html</ref><ref>New Zealand Ministry for the Environment. "Summary of the proposed changes to NZ-ETS. September 2009. http://www.mfe.govt.nz/publications/climate/emissions-trading-bulletin-11/index.html</ref> and in the European Union<ref>Parker, Larry. <i>Climate Change: The European Union's Emissions Trading System</i>. July 31, 2006. Congressional Research Service, Library of Congress. http://fpc.state.gov/documents/organization/70317.pdf</ref>, and a similar, successful program for [[sulfur dioxide]] and nitrogen oxides was implemented in the U.S. under President [[George H.W. Bush]] as an amendment to the [[Clean Air Act]]<ref>U.S. Environmental Protection Agency. "Acid Rain Program 2007 Progress Report." http://www.epa.gov/airmarkt/progress/arp07.html</ref>, a "carbon currency" in the U.S. still has many logistical hurdles and has the potential for abuse.<ref>[http://www.msnbc.msn.com/id/18180878/ MSNBC] Devil is in details of carbon cap system</ref>

The [[Intergovernmental Panel on Climate Change]] produced a report for the [[International Energy Agency]] (IEA) which states that the price for reducing human CO₂ 50% by the year 2050 will cost an estimated $45 trillion dollars or ''1.1 per cent of average annual global [[GDP]]''.<ref>[http://www.businessgreen.com/business-green/news/2218500/iea-calls-trillion-energy], Businessgreen.com, IEA calls for $45 trillion energy "revolution", June 6, 2008</ref>

The [[Intergovernmental Panel on Climate Change]] produced a report for the [[International Energy Agency]] (IEA) which states that the price for reducing human CO₂ 50% by the year 2050 will cost an estimated $45 trillion dollars or ''1.1 per cent of average annual global [[GDP]]''.<ref>[http://www.businessgreen.com/business-green/news/2218500/iea-calls-trillion-energy], Businessgreen.com, IEA calls for $45 trillion energy "revolution", June 6, 2008</ref>