Greenhouse effect

Greenhouse effect

The scientific consensus is that the increase in atmospheric greenhouse gases due to human activity has caused most of the warming observed since the start of the industrial era and that the observed warming cannot be satisfactorily explained by natural causes alone. This attribution is clearest for the most recent 50 years, which is the period when most of the increase in greenhouse gas concentrations took place and for which the most complete measurements exist.

The greenhouse effect was discovered by Joseph Fourier in 1824 and first investigated quantitatively by Svante Arrhenius in 1896.It is the process by which absorption and emission of infrared radiation by atmospheric gases warm a planet's lower atmosphere and surface. Existence of the greenhouse effect as such is not disputed even by those who do not agree that the recent temperature increase is attributable to human activity. The question is instead how the strength of the greenhouse effect changes when human activity increases the atmospheric concentrations of greenhouse gases.

Naturally occurring greenhouse gases have a mean warming effect of about 33 °C (59 °F), without which Earth would be uninhabitable.The major greenhouse gases are water vapor, which causes about 36–70 percent of the greenhouse effect (not including clouds); carbon dioxide (CO2), which causes 9–26 percent; methane (CH4), which causes 4–9 percent; and ozone, which causes 3–7 percent.

Human activity since the industrial revolution has increased the amount of greenhouse gases in the atmosphere, leading to increased radiative forcing from CO2, methane, tropospheric ozone, CFCs and nitrous oxide. The concentrations of CO2 and methane have increased by 36% and 148% respectively since 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 continuing to rise due to burning of fossil fuels and land-use change. The future rate of rise will depend on uncertain economic, sociological, technological, and natural developments. The IPCC Special Report on Emissions Scenarios gives a wide range of future CO2 scenarios, ranging from 541 to 970 ppm by the year 2100.Fossil fuel reserves are sufficient to reach this level and continue emissions past 2100 if coal, tar sands or methane clathrates are extensively exploited.

Forcing

Forcing

The Earth's climate changes in response to external forcings, including changes in greenhouse gas concentrations, variations in Earth's orbit around the Sun,changes in solar luminosity, and volcanic eruptions. The thermal inertia of the oceans and slow responses of other indirect effects mean that climate can take centuries or longer to adjust to changes in forcing. Climate commitment studies indicate that even if greenhouse gases were stabilized at 2000 levels a further warming of about 0.5 °C (0.9 °F) would still occur.

Global dimming, a gradual reduction in the amount of global direct irradiance at the Earth's surface, may have partially counteracted global warming during the period 1960-1990. Human-caused aerosols likely precipitated this effect. Scientists have stated with 66–90% confidence that the effects of human-caused aerosols, along with volcanic activity, have offset some of the warming effect of increasing greenhouse gases.

Ozone depletion, the steady decline in the total amount of ozone in Earth's stratosphere, is sometimes cited in relation to global warming. Although there are a few areas of linkage the relationship between the two is not strong.

Global warming

Global warming

Global warming is the increase in the average temperature of the Earth's near-surface air and the oceans since the mid-twentieth century and its projected continuation. Global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 100 years ending in 2005.The Intergovernmental Panel on Climate Change (IPCC) concludes that anthropogenic greenhouse gases are responsible for most of the observed temperature increase since the middle of the twentieth century,and that natural phenomena such as solar variation and volcanoes probably had a small warming effect from pre-industrial times to 1950 and a small cooling effect afterward.These basic conclusions have been endorsed by more than 40 scientific societies and academies of science,including all of the national academies of science of the major industrialized countries.

Climate model projections summarized in the latest IPCC report indicate that global surface temperature will likely rise a further 1.1 to 6.4 °C (2.0 to 11.5 °F) during the twenty-first century. The uncertainty in this estimate arises from the use of models with differing climate sensitivity, and the use of differing estimates of future greenhouse gas emissions. Some other uncertainties include how warming and related changes will vary from region to region around the globe. Most studies focus on the period up to 2100. However, warming is expected to continue beyond 2100, even if emissions stop, because of the large heat capacity of the oceans and the long lifetime of carbon dioxide in the atmosphere.

Increasing global temperature will cause sea levels to rise and will change the amount and pattern of precipitation, likely including expansion of subtropical deserts.The continuing retreat of glaciers, permafrost and sea ice is expected, with the Arctic region being particularly affected. Other likely effects include shrinkage of the Amazon rainforest and Boreal forests, increases in the intensity of extreme weather events, species extinctions and changes in agricultural yields.

Political and public debate continues regarding the appropriate response to global warming. The available options are mitigation to reduce further emissions; adaptation to reduce the damage caused by warming; and, more speculatively, geoengineering to reverse global warming. Most national governments have signed and ratified the Kyoto Protocol aimed at reducing greenhouse gas emissions. A successor to the first commitment period of the Kyoto protocol is expected to be agreed at the COP15 talks in December 2009.

Eco-innovation as a Technological Term

Eco-innovation as a Technological Term

The most common usage of the term “eco-innovation” is to refer to innovative products and processes that reduce environmental costs. This is often used in conjunction with eco-efficiency and eco-design. Many industries have been developing innovative technologies in order to work towards sustainability. However, these are not always shmet practical, or enforced by policy and legislation

Eco-innovation as a Social Process

Another position held (for example, by the organisation Eco Innovation) is that this definition should be complemented: eco-innovations should also bring greater social and cultural acceptance. In this view, this 'social pillar' added to James's (1997) definition is necessary because it determines learning and the effectiveness of eco-innovations.

This approach gives eco-innovations a social component, a status that is more than a new type of commodity, or a new sector, even though environmental technology and eco-innovation are associated with the emergence of new economic activities or even branches (e.g., waste treatment, recycling, etc). This approach considers eco-innovation in terms of usage rather than merely in terms of product. The social pillar associated with eco-innovation introduces a governance component that makes eco-innovation a more integrated tool for sustainable development.

Ecovation is the process by which responsible capitalism aligns with ecological innovation to construct products which have a generative nature and are recyclable back into the environment for usage in other industries.