"The greatest moral issue of our time" was how former Australian Prime Minister, Kevin Rudd, referred to the issue of greenhouse gas emissions, particularly carbon dioxide, stemming from human activities. Mr Rudd's views are supported by many other statesmen, though some, including Tony Abbott and former Czech President Vaclav Klaus take a contrary view.
Carbon dioxide emissions, largely derived from burning fossil fuels, have been increasing since the industrial revolution. Most scientists consider they have some warming effect though the estimates of the extent vary. Human derived emissions only became of sufficient magnitude to be potentially significant to the global warming they are said to cause during the past forty years. Although the theory of global warming has strong scientific support, in spite of carbon dioxide component within the atmosphere continuing to grow, world temperatures have not risen in the years since 1995.
The economic consequences of measures taken to reduce emissions and the often comical attempts to justify action by individual nations are the main themes addressed in the material on this site. The costs of countering emission levels are significant even if the world acts in unison. The costs are formidable if an individual nation acts alone - especially a nation like Australia which would deny itself the advantage of its low cost fossil fuels. The measures used to combat human induced emissions include taxes or caps on rights to emit, requirements to use energy from renewable and other non-fossil sources, subsidies and bans, and standards that reduce energy consumption.