Greenhouse Gases

How does infrared radiation reach the Earth?

• High energy, short wavelength infrared radiation from sun passes through atmosphere + reaches Earth’s surface.

• Some is absorbed by Earth.

• Lower energy, longer wavelength radiation reflected by Earth’s surface.

What do greenhouse gases do?

Absorb outgoing infrared radiation, increasing the Earth’s temperature.

What are examples of greenhouse gases?

Carbon dioxide, water vapour and methane.

Why are greenhouse gases important?

Without them the Earth would be too cold for water to be liquid and wouldn’t be able to support life.

How have human activities impacted the atmosphere over the past 100 years?

Carbon dioxide has increased as amount of fossil fuels being burnt has increased.

How does fossil fuel burning affect the Earth?

Fossil fuels contain carbon that’s been locked up for millions of years. Burning them releases carbon dioxide into the atmosphere.

How does deforestation affect the Earth?

Leads to increase in carbon dioxide as there are fewer trees photosynthesising.

How are methane levels in the atmosphere increased?

• Decomposition of rubbish in landfill sites.

• Animal farming increase- produced by animals during digestion + by decomposition of waste materials.

What do many scientists believe about greenhouse gases?

Increase in greenhouse gases in atmosphere will increase the temperature of Earth’s surface and result in global climate change.

How do views surrounding climate change differ?

People may have biased views, speculation is common and opinions expressed to the public may be based on part of the evidence.

What impact could global climate change have?

• More coastal erosion.

• More frequent and severe storms.

• Changes in amount + timing of rain.

• Increased number of heatwaves.

• More droughts.

• Changes to distribution of plants and animals.

• Food shortages- farming land poor

What is a carbon footprint?

Amount of carbon dioxide or other greenhouse gases a product, service or event emits over its full life cycle.

How can you reduce a carbon footprint?

• Use more alternative energy supplies e.g. solar energy.

• Waste less energy.

• Carbon capture and storage (CSS) to prevent CO₂ being released.

• Carbon taxes/licenses to deter companies/individuals from picking options that emit a lot greenhouse gases.

• Carbon off-setting through activities like tree planting.

• Encouraging carbon-neutral products

What are problems surrounding reducing the carbon footprint?

• Scientists disagree over causes and consequences of climate change.

• Lack of info in general population.

• People reluctant to change lifestyle.

• Economic - expensive to use safer energy rather than cheap fossil fuels.

• Countries disagree over what to do.