Weather is the condition of the atmosphere at a particular time and place, with regard to the temperature, moisture, cloudiness and so on.
Climate is the general condition of the atmosphere at a particular location over a long period of time, usually after approximately 30 years.
Permafrost is where soil, rock or sediment that is frozen for more than two consecutive years.
Do we have evidence for climate change? Yes! We can see this through ice melting and sea level rise. For example, since the early 20th century, Mt Hood has lost more than a third of its ice.
So, what are the causes of climate change?
Factors that have an impact on the Earth’s climate can be long-term or short term, natural or artificial.
Natural changes in climate:
Long term changes- orbital changes.
Milankovitch cycles are the shapes in which the earth orbits the sun and at what angle.
Short term changes- sun spots, volcanoes, oceanic oscillations.
But the earth's global temperature has recently risen to the extent where it has been too fast for long-term changes, but too persistent for short-term changes. The decided answer is rising carbon dioxide levels! Levels have increased above what has been seen in the last 400,000 years.
The temperature of the earth is dependent on solar input and the re-radiated energy emitted from the earth. In other words, the sun directs photons onto the earth and the earth reflects that energy. Thus, earth temperature is a consequence of an equilibrium between the two. Greenhouse gases (such as carbon dioxide, methane and nitrous oxide) absorb re-radiated energy and store it in the earth’s atmosphere, thus warming the planet.
Changes in the energy flow will influence the radiation balance and earth temperature.
The order of the most abundant greenhouse gases in the earth’s atmosphere is as follows: water vapour, carbon dioxide, methane, nitrous oxide, ozone, chlorofluorocarbons, hydrofluorocarbons. Methane is approximately 30 times more potent as a heat-trapping gas than carbon dioxide. We might want to reduce the amount of cow’s we are breeding! Nitrous oxide is over 200 times more damaging than carbon dioxide.
A summary of temperature change over the last 100 years.
If you ever find yourself bored you could maybe consider looking at the average earth temperature at an exact point in time. Global mean surface temperatures have risen by about 1.2oC since the beginning of the 20th century. It has taken longer for ocean regions to rise than land regions. Over the last 50 years on land, the rate of warming has approximately doubled that over the last 100 years. A massive concern is arctic temperatures having risen above twice the global average rate.
So why is climate change a concern? Global warming does not mean we get more fun in the sun, sadly. Climate change leads to reduced air quality (from pollution), an increase in vector-borne diseases, extreme weather (some will get terrible dry seasons leading to crop failure, whilst other places may experience extreme flooding), and is ultimately bad for our economy. Having said this, there are some benefits to climate change…