Greenhouse gases

Vocabulary

unequivocal - недвусмысленный, определённый; ясный;

to impact – влияние, воздействие

greenhouse effect – парниковый эффект

emission – выброс в атмосферу, распространение, выделение

to release – пускать, сбрасывать

to trap – ловить, собирать

to induce – заставлять, побуждать, вызывать

exhaust – выхлопные газы

to suspend – приостанавливать, прекращать

Read the text and answer the following questions:

1. Give evidence of the world warming.

2. What is greenhouse effect?

3. What is the role of greenhouse gases in climate change?

3. What does the energy balance depend on?

4. What is the role of human activity in the world warming?

The concentration of CO2 in the atmosphere reached 384 part per million (ppm) in 2007, an increase of over 30% from pre-industrial levels of 280 ppm over a century ago and far beyond the natural range of concentrations over the last 650,000 years. The latest estimates of emissions in 2004 produced by human activity, or 'anthropogenic' emissions, totaled 49 gigatonnes of carbon dioxide equivalent (GtCO2eq), a nearly 25 per cent increase from 1990 levels of 39.4 GtCO2eq. Carbon dioxide is the predominant global greenhouse gas, making up over 75 per cent of total emissions, and is used as a baseline of comparison for other greenhouse gases.

Anthropogenic CO2 emissions are mainly a result of fossil fuel combustion, flaring (burning) of natural gas which is a byproduct of oil drilling, and cement production. The energy supply sector, which ranges from fuel mining to energy delivery to the end-user, contributes over 25 per cent of total world emissions. Industry emissions, which include both energy use and industrial processes, follow at 19 per cent, and the forestry sector which includes forest management, forest harvesting for residential and commercial uses, deforestation, afforestation, and forest biomass for bioenergy, at 17 per cent.

The agricultural and transport sector each produce 13 per cent of emissions. Agriculture is the main contributor of methane and nitrous oxide emissions. The methane results from biomass decomposition, the digestion process of livestock like cows, and rice grown in flooded fields. Chemical reactions in the soil and manure due to excess nitrogen emit nitrous oxide. Methane has a potency, or global warming potential, of about 25 times that of carbon dioxide over a 100 year period as a greenhouse emission, and nitrous oxide as a global warming potential of 298.

Fig. 1 Share of global emissions in CO2 equivalent, 2004

Дата добавления: 2014-11-06