1.3 What are the causes of climate change? a)The evidence for climate change b)The atmospheric processes that result in climate change c)The relative role of environmental and human factors in recent climate change

Evidence for climate change

Greenhouse gases The greenhouse effect and global warming are 2 different things.

If greenhouse gases weren’t around…. If there were no greenhouse gasses, our planet would be 30°C cooler and we would not be able to live here. There are 5 greenhouse gases.

An increase of greenhouse gases has seen many changes around the globe. Watch the video and note down cause of increased greenhouse gases. Watch the video and note down the effects of global warming.

But climate has changed many times in the past, why is it such a big deal?

What do you think this map shows?

Aim To understand the link between CO2 and temperature To look at glaciers and ice sheets as evidence of global warming

What is the difference between the greenhouse effect and global warming?

Figure 1: Vostok ice core records for carbon dioxide concentration and temperature change.

Facts: 10/geog/climate-change/eng/global- patterns.html Globally, clearing forests by burning trees has released about 1.6 billion tonnes of carbon dioxide CO2 into the atmosphere. An area of Brazilian rainforest equivalent to the size of Wales was cut down in 2001.

GREENHOUSE GAS EMISSIONS IN WALES Estimated Emissions (million tonnes carbon equivalent) in Wales 2003 Carbon dioxide11.6 Methane1.0 Nitrous oxide0.9 Total greenhouse gases (a)13.7 (a) Also includes hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride.

WHO PRODUCES GREENHOUSE GASES IN WALES? Greenhouse gas emissions in Wales [Megatonnes of Carbon] Sector Energy Industry Manufacture [energy] Transport Other sectors [energy] Industrial processes Agriculture [non energy] Land-use change* Waste *vegetation is a SINK, not a SOURCE of CO 2 emissions and therefore the - represents the store of carbon rather than an emission of CO 2

The greenhouse gases Carbon dioxide- is responsible for % of global warming. Atmospheric CO2 concentration was 270ppm before the industrial revolution. In 2010 it reached 390ppm. Methane- In 1750 the atmospheric concentration of methane was 700ppb. In 2010 it was 1,850ppb.

The greenhouse gases Nitrogen Oxide- causes about 6% of global warming. Concentration has risen from a pre- industrial level of 275ppb to around 315ppb now. Ozone- has been depleted in the stratosphere because of the release of CFC’s. However, humans create ozone in the troposphere as sunlight reacts with nitrogen oxide and hydrocarbons from vehicle emissions.

The greenhouse gases Chlorofluorocarbons- Although their use is being phased out, they have a lifespan of over 100 years and so continue to be in the environment. In the troposphere they act as a greenhouse gas, in the stratosphere they destroy ozone.

Anthropogenic = caused by humans.

Glacial retreat as evidence for global warming. Mean global temperature is rising. Although temperature has fluctuated in the past (Little ice age and medieval warm period) we have recently seen significant changes in glaciers from all around the world. Since 1960 we have lost an estimated 8,000km3 of ice.

Mt Kilimanjaro

Mt Everest

Ice shelf collapse

Quick on the draw

Homework: Create a table of at least 8 impacts of global warming and their location.