THE GREENHOUSE GASES

The greenhouse effect is the trapping of heat around Earth.

A tiny number of gases in the atmosphere can trap heat around the Earth. This gases keep the Earth warm.

The greenhouse gases are like a blanket: if they are in the right thickness, Earth won’t be too cold or hot.

The Earth’s atmosphere is made up of nitrogen (about 78%) and oxygen (about 21%).

The traced gases 1% regulate the climate.

These are the gases: Water vapour- It’s the most

common. It’s the 60% of the natural greenhouse effect.

THE GREENHOUSE GASESTHE GREENHOUSE GASES

THE GREENHOUSE GASES

Carbon dioxide CO2 It comes from:

*plants decay *volcanoes erupt *animals breathe. Human activities increase the

CO2 levels and are the main gas responsible for global warming.

Methane It comes from: *animals as waste gas

*rooting plants and rubbish.

*burning fossil fuels.

Waste- residu decay- descomposicióRoot- arrels breathe- respiració

Nitrous oxide . It’s the most powerful greenhouse gas.

Ozone It’s helpful in the stratosphere but it’s dangerous in the troposphere.

It form when the sunlight reacts with fumes from and trucks.

Halocarbons CFCs were used as spray , solvents, cleaners and coolants …SES

THE GREENHOUSE GASESTHE GREENHOUSE GASESTHE GREENHOUSE GASESTHE GREENHOUSE GASESTHE GREENHOUSE GASES

THE GREENHOUSE GASES

The greenhouse effect

Not all the heat we feel on Earth comes from the Sun. Most of this heat comes from Earth itself, which is trapped and sent back down by greenhouse gases.

Greenhouse gases let enter

high-energy radiation from Sun. This warms the Earth but not the atmosphere.

Let- permetre

As Earth warms up, it gives heat as low-energy infrared rays.

Only a few pass through the greenhouse gases.

The greenhouse effect

The greenhouse effect

The greenhouse gases trap most of infrared rays. This heats the atmosphere and heats the Earth.

The greenhouse effect

ENHANCED EFFECT

Without greenhouse gases, Earth’s surface temperature would be -18º C, Too cold for life.

Natural greenhouse gas levels make it a comfortable 15.5ºC.

But when more greenhouse gases are added, for instance by human activities, the greenhouse effect is enhanced and the global temperatures start to rise.

Nowadays, the levels of CO2 (carbon dioxide) and methane in the atmosphere are highest than 160,000 years.

A quarter of the CO2 in the atmosphere was added by human actions.

Enhance- creixement,millora