We can think about changes that occured on a geological or over many hundreds of thousands (even millions of years) of years. And... We can think about smaller changes that occurred within those periods. So, the period of the last 12,000 years is a shorter time in which we can look at different kinds of evidence.

Climate change over ‘geological time’. On the next slide, only this purple part of ‘time’ is shown...

The evidence?

landscape This U shaped valley is made by ice erosion. The climate must have been warmer once upon a time. It may have been made 100,000s of years ago.

Ice cores provide a lot of past climate data from 800 – 800,000 years ago. This is the famous Vostok research station ice drill.

And historical (more recent changes)...look at the x axis.....

The evidence?

Pollen records Scots Pine (Pinus sylvestris) Salix – willow tree

A varve A mud deposit from the bottom of a lake may contain lots of preserved pollen

A fair on the the frozen River Thames in London. This regularly occurred in the Little Ice Age and it was known to be unusual – that’s why artists painted it.

Trees grow more slowly in winter than summer (or even stop growing). So we see a darker more compact ‘ring’ for the winter period. Also, if there are colder years the rings will be generally closer together. We can look at live and dead (preserved) trees.

Use the following words to fill the blanks and then stick it in: extreme temperature absorb hotter hurricanes atmosphere climate increase What is Climate Change? Climate change: The Earth's ________ has been changing for hundreds of millions of years. Climate change doesn't necessarily mean things will get _______; most places will see more _________ weather (e.g. heavier rainfall, more snow, longer droughts, more _________, and more heat waves). Global warming: the _________ in the average ____________ of the Earth's near-surface air and oceans in recent decades and the future. Most of the observed increase since the mid-20th century is likely due to the Greenhouse Effect (greenhouse gases such as CO2 __________ outgoing heat from the Earth and trap it in the ___________).

Climate change: The Earth's climate has been changing for hundreds of millions of years. Climate change doesn't necessarily mean things will get hotter; most places will see more extreme weather (e.g. heavier rainfall, more snow, longer droughts, more hurricanes, and more heat waves). Global warming: the increase in the average temperature of the Earth's near-surface air and oceans in recent decades and the future. Most of the observed increase since the mid-20th century is likely due to the Greenhouse Effect (greenhouse gases such as CO2 absorb outgoing heat from the Earth and trap it in the atmosphere).

Causes of climate change Task (in pairs): 1. Read through the statements. 2. Sort the statements into causes and impacts. 3.Sort the statements into physical (natural) and human causes of climate changes. 4. Use the statements to complete the table, the number of human and physical causes may not be equal.

Possible Solutions?