In today’s information age it’s all too easy to be inundated with too much information, and to be unable to tell what to believe. This is all too true when it comes to global warming and climate change. Most commonly we see ‘weather’ and ‘climate’ conflated in the media, meaning that whenever there is a spell of cold weather we see news reports abounding that global warming cannot be true. So in this post we’re addressing that, and some of the other most common climate change myths.
Cold winters mean that global warming can’t be real
We have a tendency to relate climate change directly to the weather that we see out of our windows. When there are unseasonable warm spells we take this as evidence that global warming is real. If it’s cold in the winter, we take this as evidence that global warming may not be as much of a problem as we think.
The important distinction here is between climate and weather. Weather refers to day-to-day fluctuations in temperature, precipitation and so on. Climate refers to the pattern of these day-to-day fluctuations over a long period of time in a specific location, for instance the dry, warm climate of much of the Mediterranean compared to the harsh cold conditions of the Arctic tundra. So, the variations that you see daily in weather don’t have a direct relation to long-term climate change, and need to be investigated more thoroughly in order to reach conclusions.
For instance, our weather systems rely on jet streams (high altitude, east-to-west winds), which are propelled forward by the different between warm air from the tropics and cold air from the Arctic. Global warming is causing air in the Arctic to become warmer, which then means that the jet streams slow and normal weather patterns are affected. Scientists have found links between the warmer Arctic air and cold winters: warmer temperatures cause the jet stream to take ‘wild swings’ which causes cold air to reach parts of the world it wouldn’t usually. This is why we have seen extremely cold winters in the eastern states of the USA in the winter of 2019.
Another thing to consider within this myth is snowfall, with many claiming that increased snowfall demonstrates that global warming cannot be real. In actuality, warming causes an increased amount of moisture in the air, which leads to more precipitation. This includes snowfall, where conditions that produce snow are in play. Therefore, increased snowfall does not contradict global warming, and instead is consistent with our expectations of the climatic impacts of warming.
“Britain’s big freeze is the start of a worldwide trend towards colder weather that seriously challenges global warming theories.”
The Daily Mail, reporting on the winter of 2009–10
We can’t fulfill our energy demands on wind and solar alone
People commonly believe that we couldn’t run on 100% renewable energy, seeing renewables as too expensive to be our only source.
It’s true that for a long time fossil fuels were the cheapest form of energy. This is largely due to a low market price driven by demand and dominance in the market. There’s also a difference between the market price and the true cost when it comes to fossil fuels — they may be cheap in the moment, but we’re generating future costs through healthcare and environmental clean up, for instance. Economists refer to these costs as ‘externalities’.
Alongside this, we’ve also seen the price of solar and wind energy drop in recent years due to a decrease in equipment costs, and an increase in investment. In 2016, China invested $103 billion in solar projects. This means that now wind and solar energy are as cost effective, or even more cost effective, than energy from burning fossil fuels.
The Earth is the hottest it has ever been
During the Eocene period, fifty million years ago, it was around 10 degrees Celsius hotter than it is today, on average.
Many climate skeptics use this to argue that global warming is nothing to worry about, and is instead part of naturally fluctuating temperatures. What this argument ignores, though, is how fast the temperature is changing right now. The natural warming periods of the past developed over thousands (possibly even millions) of years, whereas today we’ve seen warming increase over decades.
“It’s not how much the temperature has gone up — that’s only around 1 degree over the past 100 years. What’s unprecedented is the rate of change.”
Professor Adam Scaife, Met Office.
Climate models are unreliable
To some extent, this is true: we can’t be certain that climate models are completely accurate. However, predictions that have been made by climate models have now been observed in reality, which suggests that they are broadly reliable in terms of predicting trends. Some models have also been shown to be too conservative: melting of Arctic sea-ice, for instance, was around 40% greater between 2007–2009 than predicted in IPCC climate models.
The key thing to be aware of in terms of climate models is that all existing climate models are unable to predict warming from the 1800s to the present day without taking our rising levels of carbon dioxide into account. You can see this in the graphs below. The red line is our actual observations of temperature increase, and the grey line is the expected temperature variation.
Graph a) demonstrates how we would have expected temperature to change with only natural impacts such as volcanic activity or solar variation. Graph b) demonstrates how we would have expected temperature to change with only anthopogenic (i.e. man-made) impacts. Graph c) combines both a and b to show how we would have expected temperature to change including both natural and man-made impacts.
As you can see, it is in graph c that the red line (actual observations) and grey line (expected change) are the closest aligned.
Humanity isn’t to blame for climate change
Discussing the reliability of climate models leads us neatly into the myth that ‘it’s not us’ and that we would be seeing these changes in our climate without human input.
The simplest argument against this is the same graphs we looked at in the previous point. No scientist has come up with a climate model which can explain the temperature changes that have now been observed, without including the carbon dioxide emissions caused by human activity.
In terms of how human activity is causing climate change, the basic argument goes like this:
- Humans are currently emitting around 29 billion tonnes of carbon dioxide every year.
- Satellites have measured that less heat is escaping from the Earth’s atmosphere, at the exact wavelengths that carbon dioxide absorbs.
- Measurements of surface temperature have found that the heat which is not escaping is returning to the Earth, warming the surface.
Climate change doesn’t matter because we will adapt to it
It’s true that human beings and other Earth-dwelling species do adapt to changing conditions. However, the sheer speed of our human-induced climate change, compared to natural fluctuations, means that only some species will be able to adapt quickly enough, and survive.
We are already seeing some species begin to adapt to the changing climate. Many species of butterfly, for instance, are starting to live higher up in the mountains. Nine-banded armadillos have moved into North Carolina, from their previous habitats further south. European larger banded snails have actually lightened the colour of their shell, reducing their body temperature.
But this isn’t true for all species. Particularly, for species which are already endangered or in lower numbers (some large mammals, for instance) it will be much harder to adapt as they have a much smaller gene pool to play with. They also live longer, meaning there are less generations with which to adapt. Short-lived species like fruit flies, on the other hand, will be more likely to be able to handle climate change.
Climate change causes extreme weather
We’ve already discussed the fact that cold winters don’t mean that climate change isn’t real. Similar to that is the way that extreme weather events, particularly unseasonable warm spells and flooding, are now often directly connected to global warming in the media.
This isn’t strictly true. Specific weather events can’t always be directly attributed to climate change, and we would expect to see fluctuations in our weather system regardless. But what we can say is that global warming makes extreme weather events more likely, and potentially more deadly.
“Asking whether a specific event is down to climate change is really tricky, but you can look at whether that type of event is more likely. It’s all about the risk of certain events changing. You can say that a specific type of event is more likely.”
- Professor Adam Scaife, Met Office
Scientists still don’t agree on global warming
This simply isn’t true. Major scientific institutions no longer dispute the idea that we are seeing global temperature increases due to human activity: the basic idea that carbon dioxide causes warming and that humans are responsible for the unprecedented rise in carbon dioxide, is very well established. The figure usually cited is that over 97% of peer-reviewed published work (therefore seen to be reliable) supports the idea that warming is directly related to human activity.
What scientists do continue to debate the exact details of how much warming we can expect and what the likely impacts are.
Climate change will cause human extinction
It’s highly unlikely that climate change will cause the end of humanity and/or the planet we live on.
However, it will have significant impacts on people, and particularly on some of the most vulnerable people in our society. This is particularly due to food security: a more variable climate will mean flooding, droughts, and temperature variations which will impact our crops. This means a risk to the livelihoods of many people living in rural areas (mostly the poor), as well as starvation caused by a lack of food.
For more information on any of these arguments, or to read more common climate change myths, I’d definitely recommend taking a look at the Skeptical Science website.