Is CO2 a greenhouse gas that causes the Earth to warm up?
Yes, the basic physics have been fully validated.
Is the rise in atmospheric CO2 since modern records began mainly due to human activity?
Yes. (Although at times in the distant past, especially before humans evolved, there have been far higher concentrations of CO2.)
Have global temperatures increased since the start of instrument records around 1850?
Yes. There have been periods of both rising and falling temperatures but the overall trend is upwards. (The trend is actually flat since 1998.)
Is the rise in global temperatures since the 1940’s mainly due to human activity?
No, this increase in temperature is no different to many others that have happened before. I believe the reasons put forward by those who claim it is unique are wrong. I do accept that human activity must cause some warming, but it is very unlikely that it will cause dangerous changes to our climate.
Why don’t you accept the predictions of future warming made by many climate scientists?
Because their predictions have so far been proved wrong. If their predictions started coming true, I would start to believe them. Simple.
Why do you think their predictions are wrong?
There are still many things we do not understand about the Earth’s climate. For example, nobody knows exactly why ice ages begin and end. Instrument records are far too short for us to identify all the processes at work in the atmosphere. The effect of more or less cloud cover is poorly understood. I also have personal experience of surface stations that record climatic data, in several countries, and know that the claimed accuracy of many of them is false. Most of the predictions are based on computer models that fail to simulate major features of the climate. One day humans will be able to accurately predict our climate, but not yet.
Shouldn’t we reduce CO2 output anyway, just in case?
No. Firstly, if we took action to avoid every unlikely risk we would waste huge resources doing so. There are far more urgent problems, particularly disease and poverty. Secondly, the output of CO2 is a direct result of industrialisation, which is the surest way to lift people in developing countries out of poverty. It has also been estimated that a small amount of warming is beneficial to mankind. Finally, plants breathe CO2 in the same way we breathe oxygen, and it appears global crop yields have increased as atmospheric CO2 has increased.
Are all those who warn of the dangers of global warming involved in some sort of conspiracy?
No. It is perfectly possible for someone to look at and understand the science, and still decide that increasing CO2 will lead to dangerous climate change.
Why do you use the derogatory term ‘alarmists’?
When I use this term, I am referring to those who make absurd predictions that cannot come true, or who knowingly lie, distort the truth and smear their opponents because they think their cause is just, or who use the whole issue as a cover to further their political beliefs. Unfortunately a majority of the most prominent people who warn about dangerous global warming fall into this camp. They have hijacked a movement that should be working to keep our beautiful planet a clean and safe place for all life to live. I detest them.
What about people at the other extreme?
Sadly there are some very vocal people who believe that the greenhouse effect doesn’t exist, or that God would never allow dangerous climate change, or that the whole thing is a conspiracy designed to usher in a socialist one-world government, or that variations in Earth’s climate are driven mainly by the orbits of other planets. What would I call these people? Nutters.