Climate Change Flashcards
what evidence is there that climate change is natural
it happened before humans
what has happened since 70’s
a dramatic increase in temperature
what is the cause of the increase in temperature since 70’s
thick layer of green house gases (carbon and methane) caused by human activity. Less sun energy escapes the atmosphere so temperatures increase
What evidence is there for climate change
met office data from weather stations, satellites, weather balloons, radar and ocean buoys
what has the evidence collected found out
1 % increase in temperature in the last 10 years, warmest oceans since 1850, 19cm rise in sea level since 1900
what natural evidence is there for climate change
proxy data - tree rings, fossil pollen, ice cores - act like time capsules holdling information about climate and ocean sediment - the deeper the sediment the older it is and acts like a timeline
how do we know that solar output is not the cause of climate change
sun output is measured by observing sunspots. satelites use radio meters to measure solar energy. they have shown that solar output has actually decreased in the last 50 years and so can not be responsible for the cause of climate change
why do scientists suggest climate change is a natural phenomenon
geological evidence shows it has been happening before humans were on the planet and so must have natural causes
3 posissible natural causes of climate change
solar output
orbital change
volcanic activity
Can orbital change cause of climate change
There are 3 orbital changes
the amount of suns energy hitting earth changes because of the earths orbit.
The earths distance to the sun changes as it orbits (the sun is not directly in the centre)
When the earths tilt changes can effect the climate
earth is not a perfect sphere and can wobble on its axis
Scientists agree orbital change will not cause an ice age for at least 30,000 years
How do volcanoes effect climate change
effect climate change temporarily as they cause volcanic aerosols which reflect sunlight and reduce suns heat entering the atmosphere. Temperatures drop.
what is the greenhouse effect
it is what keeps earth warm enough for life
Suns infared rays enter atmosphere and heat is reflected from earths surface some heat is trapped to keep earth warm and some is reflected out of the atmosphere
what is enhanced greenhouse effect
human activity has increased the level of greenhouse gases that naturally exist
what human activities generate green house gases
burning fossil fuels in industry, agriculture, transport, heating and deforestation
how does burning fossil fuels cause climate change
account for over 50% of greenhouse gas.
Burning them releases carbon diocide into the atmosphere
fossil fuels are used in transport, heating homes, and manufacturing.
as population increases level of fossil fuels increase