It is good to clear up some things at the beginning, and people working for gas/oil/energy companies especially should come clean about their views regarding climate change. We think global warming is real, and uncertainty strengthens the case for action, not weaken it.

So here we go: 

1. Greenhouse gases do increase in the atmosphere, and humans are causing it. CO2 concentrations went from about 280 ppm (part per million) to about 390 ppm now. (check out the latest reading here: http://co2now.org/). Concentrations are increasing by about 2 ppm per year. This should be fairly uncontroversial, but some sceptics are denying that the increase in CO2 concentrations is caused by humans.
2. Increasing CO2 and other greenhouse gases in the atmosphere does eventually cause a warming of the climate. At the root of it, this is physics, and there is fairly high confidence regarding it, even if it is masked by the normal variability of year-to-year weather. It is nevertheless a favourite area of doubters – some argue for example that the causation between CO2 and higher temperatures is somehow the reverse of what most scientist think. But unfortunately, bad things do not go away of you close your eyes.
3. The exact way and timing how the climate will evolve in reaction to greenhouse gas emissions is highly uncertain. The atmosphere is a very complex system, there are various feedback loops and other effects. Some of these are slowing the change - for example, oceans absorb about half of the CO2 that humans are emitting. There are also positive feedback loops - declining ice cover results in a darker surface that absorbs heat better and contributes to further warming. And there may be tipping points that may result in fast, runaway climate change (the potential release of methane hydrates from permafrost bogs for example).
4. Uncertainty does strengthen the case for action, not weaken it. The higher the uncertainty, the more likely are “tail events”, catastrophic large scale climate changes. This is difficult for the human mind to intuitively comprehend, we tend to neglect small probability/high impact events. Uncertainty also makes presenting climate change risks in everyday language difficult. There is no definite limit of CO2 concentration that would make a catastrophe certain – the 450 ppm/2C limit was introduced as a way to convey increasing risks, but there is no guarantee that we avoid a climate catastrophe is we stay within that limit, or that we have one of we pass it. It is “only” that the risks are continuously increasing with higher CO2 concentrations.
5. Climate change is about people, and not the “Planet” or “Nature”. Earth has gone through violent climate changes in the past, and some of it was probably very fast. There were at least 5 large scale mass extinction events in the history of Earth, the climate varied between “Snowball Earth” to “Hothouse Earth” and life still survived. It will survive a human induced climate change of a few degrees as well, while humans may not. The relatively stable climate of the past 10 thousand years is the exception and not the rule, but this is the exception that people got used to. Fast climate change could mean a large scale collapse of human capacity to produce food and other amenities, and a mass extinction of humans well before most other species. It is primarily because of selfish reasons we should be concerned.
6. Climate change is not an easy issue to solve, and it is not a conspiracy that it is not solved. There is huge inertia in most things that emit CO2 and other greenhouse gases. Power plants cost billions of dollars and last decades. It would be generally a good idea to be more open to change than societies and economies are currently capable of, but at the moment it is practically impossible to quickly change our energy infrastructure. What is more, current non-CO2 emitting technologies are inferior in some other aspect – most importantly cost – compared to CO2-emitting ones. Even in the best case, CO2 emission is likely to decline only slowly.
7. Climate change will be “solved” one way or another. We are biased, and we prefer solutions that involve the preservation of human civilization and prosperity (not to mention sheer survival). For that to happen, in the longer run (several decades), net emission of CO2 will have to be stopped. In the meantime, we are running risks and are balancing between those risks and the costs of mitigating them. We may get that balance wrong. No wonder many people are tempted to deny that we are in this uncomfortable position.
8. Climate change will not be solved by consuming less. People, given a choice, clearly prefer to consume a lot more (energy and other things) than it is compatible with no CO2 increase, given current technologies. Moral pressure will not solve the problem, and dictatorship, even a green one, is not a good idea. Only technological development could solve the problem, and we should get better at that, as well as at climate science (so that we can see the risks more clearly). Because of its close ties to questions of consumption and distribution among nations and generations, climate change is an inherently political issue, and this will not change. Still, economists as well as climate scientists may give important guidance to politicians in order to evaluate and minimize long term risks and promote efficient means to tackle the issue.
9. Climate change is a long-term story. By that we mean decades. It does not really matter whether we reduce CO2 emissions this year or next. In fact if we can do a lot more emission reduction in the future when it is cheaper, we should do it then, as opposed to now, at a high price. But to formulate an optimal policy, there is also a need to estimate how much it will cost to reduce CO2 in the future, and whether society is willing to pay that price. Also, existing energy infrastructure is also in place for decades, creating vested interest to keep it going, which may slow change in the future. It is not an easy calculation, and this is why it is always suspicious when someone is very definite about the right course of action.

We will be writing in more detail about these issues, but then we do not have to reiterate these basics about our standpoint.