The Earth’s climate is changing. Or is it?
While most people can agree that the climate is changing – It always is – there are differing opinions about how and what’s causing it. Scientists have concluded that there is man-made climate change going on and that the most important contributing factor is the emission of greenhouse gases, such as CO2, causing global warming.
But how clear-cut is this case, really? Is there any merit to the sceptics’ claims that there is an outbreak of climate hysteria going on, or are they just misinformed and overly suspicious?
In this article, we examine the facts and myths of climate change and give you the sources, for further reading.
1. The global temperature is rising
It is a that the average global surface temperature has risen 1.62 degrees Celsius since the end of the 19th century. It is also a fact that most of the change has happened during the last 35 years, which coincides very well with the increasing amount of greenhouse gases in the atmosphere.
The temperature is not actually fluctuating, as some claim. It’s been on a steady rise and in fact, the trend has been accelerating. Global warming is real!
2. Polar ice sheets are shrinking
Ice sheets fluctuate naturally and they have been doing so, naturally, for thousands of years. However, nothing in nature can explain the extreme rate of polar ice caps shrinking that scientists have seen during the last decade. Especially in the Arctic, the trend is clear.
The ice cap is melting at an accelerated pace and it does not have time to re-grow during the winters. As the development continues we will start seeing severe secondary effects on a global scale.
3. Glaciers are retreating
While polar ice caps may be difficult to follow, anyone can see glaciers retreating and getting smaller.
Glaciers can shrink for two reasons:
- Reduced snowfall in winter
- Warmer weather during the summer
Currently, we see both of these things happening simultaneously, and everywhere in the world glaciers are shrinking. Glaciers are great heat sinks and their retreat causes accelerated warming everywhere.
4. Oceans are getting warmer
The oceans are vast and the water in them can absorb enormous amounts of energy with only small changes in temperature. That is why it’s so alarming, and telling, that ocean temperatures have been rising steadily since the 1940s
Although the temperature is minuscule, at 0.13 degrees Celsius they represent a huge change, considering the sheer mass of water involved.
If it weren’t for the oceans, global warming would be much more severe and obvious.
5. Sea levels are rising
In 2014, average global sea levels were 6.6 cm above the 1993 averages, according to NOAA, and the 1993 level was the highest recorded average ever, at the time.
On average, sea levels continue to rise around 3 mm yearly, something which is causing big problems around the world. Why are sea levels rising?
Scientists point to two :
- Thermal expansion – As the oceans get warmer the water expands, as do all materials when you heat them.
- Ice melting – Polar ice caps, glaciers and other ice masses are retreating, contributing more water to the oceans.
6. Decreased snow cover
The evidence is clear. According to studies by NSIDC
, snow cover is decreasing every year. While this doesn’t directly affect sea levels it must be caused by something.
At the climate gets warmer more precipitation comes as rain instead of snow and the snow that falls does not accumulate as much as it used to.
7. More extreme weather
According to scientific evidence and data compiled by NASA
, the number and intensity of severe weather events have increased since the 1950s, with one exception.
The number of record low temperatures have steadily decreased. This doesn’t bode well if you want to make the case that climate isn’t changing, because it obviously is and not in a good way.
With global warming, we’re seeing more severe storms and more precipitation than ever before.
8. Ocean acidification
While the detailed chemistry is a bit much for us to cover here, it isn’t exactly rocket science. When the greenhouse gas carbon dioxide (CO2) is absorbed by water, carbonic acid is formed, making the water acidic.
It is the same thing as happens in carbonated soft drinks, only it’s happening in our oceans. Since the beginning of the industrial revolution, the pH level of the oceans surface water has dropped by 0.1.
Exact numbers aside, this is a substantial change that has real effects on life in our oceans.
Will there be any fish in the oceans of tomorrow? Well, we don’t know but if pH levels continue to drop it may have a huge impact on wildlife at sea.
9. Scientists don’t agree!
No, they don’t. Actually, scientists usually do not agree.
That’s how scientific progress is made. Only, as far as climate change is concerned, scientists actually do agree to an alarmingly high extent
There is actually a consensus that the climate is changing and that, to a large part, it is happening because of human activity in general and the emission of greenhouse gases in particular.
10. Sun activity
Among it’s a popular theme, to blame the sun for global warming. Yes, solar activity has a huge impact on our climate and the temperature of the earth, but it isn’t enough to explain what we’re currently seeing.
This has been studied by the IPCC among others and the conclusion is always the same: The sun does contribute to climate change but the variations in solar activity cannot explain more than 10 per cent of the changes in temperature that we are observing.
Science is never settled. This is as true for climate science as much as anything, but it doesn’t mean that we don’t know anything about climate change and its causes.
Scientists know a lot more today than they did just a few years ago and they will continue to learn more in the future.
This doesn’t change the fact that the climate is changing and that we are contributing to it in a substantial way. We know this already and we’re gaining better understanding every day.