Greenhouse Effect

In the 1980s scientists determined the average temperature of the Earth's surface was slowly rising. This trend is referred to as global warming. There has emerged a broad scientific consensus the cause of this rise is a build up of gases in the atmosphere.

A greenhouse is a glass house in which plants grow which lets light in and at the same time keeps heat from getting out. This heat keeps the plants warm, even when it is cold outside.

It is believed the same thing is happening with the Earth's atmosphere. It lets sunlight in and CO2 and other gases restrict this heat from escaping into space.

Anthropogenic factors are human activities that change the environment. Various hypotheses for human-induced climate change have been argued for many years though, generally, the scientific debate has evolved from scepticism to a scientific consensus that human activity is the probable cause for the rapid changes in world climate in the past several decades. Consequently, the debate has largely shifted onto ways to reduce further human impact and to find ways to adapt to change that has already occurred.

Of most concern in these anthropogenic factors is the increase of CO2 levels due to emissions from fossil fuel combustion, followed by aerosols (particulate matter in the atmosphere) and cement manufacture. Other factors, including land use, ozone depletion, animal agriculture and deforestation, are also of concern in the roles they play - both separately and in conjunction with other factors - in affecting climate change.

Human activities since the industrial revolution have increased the atmospheric concentration of various greenhouse gases, leading to increased radiative forcing from CO2, methane, tropospheric ozone, CFCs and nitrous oxide. The atmospheric concentrations of CO2 and methane have increased by 36% and 148% respectively since the beginning of the industrial revolution in the mid-1700s. These levels are considerably higher than at any time during the last 650,000 years, the period for which reliable data has been extracted from ice cores. Less direct geological evidence indicates that CO2 values this high were last seen approximately 20 million years ago. Fossil fuel burning has produced approximately three-quarters of the increase in CO2 from human activity over the past 20 years. Most of the rest is due to land-use change, in particular deforestation.

CO2 concentrations are expected to continue to rise due to ongoing burning of fossil fuels and land-use change. The rate of rise will depend on uncertain economic, sociological, technological, and natural developments.

Beginning with the industrial revolution in the 19th Century and accelerating since, the human consumption of fossil fuels has elevated CO2 levels from a concentration of approximately 280 parts per million (ppm) in pre-industrial times to around 387 ppm today. The concentrations are increasing at a rate of about 2-3 ppm/year. If current rates of emission continue, these increasing concentrations are projected to reach a range of between 535 to 983 ppm by the end of the 21st century. Along with rising methane levels, it is suggested that these changes may cause an increase of 1.4–5.6°C between 1990 and 2100 Proposals by some scientists and international coalitions, aimed at attempting to prevent drastic climate change, have suggested setting goals to try to limit concentrations of CO2 to a range of 450 to 500 ppm.
One alternative hypothesis, widely refuted, to the consensus view that anthropogenic factors are causing temperature increase is that recent warming may be the result of variations in solar activity.

Models are used to help investigate the causes of recent climate change by comparing the observed changes to those that the models project from various natural and human-derived causes. Although these models do not unambiguously attribute the warming that occurred from approximately 1910 to 1945 to either natural variation or human effects, they do suggest that the warming since 1975 is dominated by man-made greenhouse gas emissions.

The Northern Hemisphere has more land than the Southern Hemisphere, so it warms faster. The Northern Hemisphere also has extensive areas of seasonal snow and sea-ice cover subject to the ice-albedo feedback. More greenhouse gases are emitted in the Northern than Southern Hemisphere, but this does not contribute to a difference in warming between the north and south because the major greenhouse gases persist long enough to mix between the hemispheres.

Some economists have tried to estimate the aggregate net economic costs of damages from climate change across the globe. Such estimates have so far yielded no conclusive findings; in a survey of 100 estimates, the values ran from $US-3 per tonne of CO2 up to $US95 per tonne of CO2, with a mean of $US12 per tonne of CO2.

One widely publicized report on potential economic impact is the 2006 Stern Review. The report said the costs of acting to counter climate change, by stabilizing emissions of carbon dioxide in the atmosphere, might be about 1 per cent of annual global gross domestic product (GDP) by 2050. But the cost of doing nothing was found to be far greater – risking up to 20 per cent of the world's wealth. The report's methodology, advocacy and conclusions have been criticized by many economists, primarily around the Review's assumptions of discounting and its choices of scenarios. Others have supported the general attempt to quantify economic risk, even if not the specific numbers.

In a 2009 update Lord Stern revised his 2006 prediction, saying the cost of inaction would be "50 per cent or more higher" than his previous highest estimate – meaning it could cost a third of the world's wealth.

The International Panel on Climate Change (IPCC) Working Group is responsible for crafting reports that deal with the mitigation of global warming and analyzing the costs and benefits of different approaches. The 2007 IPCC Fourth Assessment Report concluded that no one technology or sector can be completely responsible for mitigating future warming. They find there are key practices and technologies in various sectors, such as energy supply, transportation, industry, and agriculture that should be implemented to reduce global emissions. They estimate that stabilization of CO2 equivalent between 445 and 710 ppm by 2030 will result in between a 0.6 percent increase and three percent decrease in global GDP.

For the purpose of this invention the 1 percent global GDP decrease suggested by the Stern Review is used for comparative purposes.

According to the IPCC Working Group, to limit temperature rise to 2 degrees Celsius, developed countries as a group would need to reduce their emissions to below 1990 levels in 2020 (on the order of -10 percent to 40 percent below 1990 levels for most of the considered regimes) and to still lower levels by 2050 (80 percent to 95 percent below 1990 levels), even if developing countries make substantial reductions.

Human nature what it is, changing current energy regimes and reducing man’s detrimental impacts on the environment will be difficult if not impossible to achieve. It is an objective of the current invention therefore to reduce the human impact of CO2 on climate change, whether or not energy regimes are changed or other impacts are lessened. In one aspect of the current invention substantial amounts of the greenhouse gas CO2 will be sequestered in vegetation planted in irrigated deserts.