[flash_zombie]

> Past periods of high CO2 do not contradict the notion that CO2 leads to higher global temperatures. Indeed, it confirms that there is a strong relationship between the two.

The relationship, at least in the smaller graph, isn't in question. The causality is. I didn't say it contradicts the causality, I say it doesn't support the causality.

If you look at the larger graph, whatever relationship there is between CO2 and global temperature becomes indiscernible.

> There are other sources of temperature change so you can't use one indicator to prove there is no effect

You can't prove a negative in the first place. Of course there's bound to be some effect, but how large is it really?

> On the right of that graph, there is a vertical red line. That's not an axis or a border, that's the recent rise in CO2 levels, and it's unprecedented.

The rise may be unprecedented, the level isn't.

> The overwhelming majority of evidence shows that human activity, mainly greenhouse gases, is causing climate change.

That's a strong statement for what it is at best a discernible correlation.

I'm willing to take it on faith. Humans cause climate change? Now what? We absolutely have to drop everything and start cooling the planet? Until the next ice age, when presumably we'll have to warm it?

[dominicr]

> The rise may be unprecedented, the level isn't. So you admit the there is a problem ;) The level hasn't been this high for over 400,000 years. How many homo sapiens were around then to adapt to that? The unprecedented rise is the problem, and it's not just CO2 and methane rising faster than should be expected, it's also the global temperature.

> That's a strong statement for what it is at best a discernible correlation. It's a strong and very valid statement, supported by a wealth of science. In this instance it's not really possible, or wise, to run multiple randomly controlled experiments on our own planet to conclusively prove the point. Instead, we have a lot of observations and modelling that allow us to run those experiments, and the weight of those say we have a problem.

> We absolutely have to drop everything and start cooling the planet? The majority consensus is not to drop everything but to continue making substantial changes to human activity to reduce warming. You personally do not need to become an eco-warrior, just more aware of the effect you're having on the planet and try to reduce it. Cooling the planet is now beyond expectations. The aim now is for it not to warm up too much.

> Until the next ice age, when presumably we'll have to warm it? That is a terribly big false equivalency! First, yes, I expect so. Second, it's totally different! Ice ages take multiple hundreds, if not thousands, of years to get going. The next ice age is not going to affect the next generation, global warming is.

The benefits to ecological improvements and the risk of climate change vastly outweigh the costs. Less pollution related illness, our limited resources will last longer, etc... The risk alone is enough to make me think that ignoring the problem is the morally wrong choice, the benefits double the equation.

[flash_zombie]

> Instead, we have a lot of observations and modelling that allow us to run those experiments, and the weight of those say we have a problem.

No, the weight of those say there will be an increase in temperature. Never mind that the weight of these have been wrong for more narrow definitions of the word "wrong":

https://www.cato.org/sites/cato.org/files/styles/pubs/public...

If those models can't predict ten years into the future with any reasonable amount of confidence, how can we trust them to predict the next 100 years?

Even then, let's say these models are more or less correct, what exactly says "we have a problem"? What problem? We already have tons of problems! Not being able to emit CO2 would be a huge problem in and of itself. What are the models to predict the actual problems caused by climate change? How good are those? Do 95% of scientists agree on them?

> The majority consensus is not to drop everything but to continue making substantial changes to human activity to reduce warming.

Okay, I don't exactly feel like making substantial changes to my lifestyle based on these predictions, especially since the impact doesn't concern me much at all. Now what? Good luck getting all that political support that you will need.

[dominicr]

> especially since the impact doesn't concern me much at all.

Yes, it usually boils down to selfishness.

[flash_zombie]

> Yes, it usually boils down to selfishness.

All lifeforms are selfish. If your solution only works on an imaginary selfless version of the human being, then it's not a solution. It's a fantasy.

[dominicr]

> All lifeforms are selfish.

This is such a crude, reductionist view that falls very short of reality. You know, it might just be you and minority that think this way.

Luckily reality shows time and time again that people in general (definitely excluding you here) have better motivations and take better decisions which consider other people.

[ThomPete]

So is denying poor nations to get out of poverty which is only possible through access to cheap and reliable energy.

[dominicr]

Your comment lacks value for at least 3 reasons:

1. A lot of the discussion at the moment is about action within the USA, Europe, Brazil and China. These are not poor countries. Brazil isn't doing great but is a significant economy. China is taking a lot of action already to move to greener tech. There is an acceptance amongst most that the richer nations should be doing most to tackle climate change, as well as helping other nations.

2. Green does not necessarily mean expensive. Look at the levelized cost of energy in different countries and green options are often cheaper or comparable to fossil fuels, even before the indirect costs are considered.

3. Green is often also the most practical solution for developing countries. In many, solar and wind are used as the infrastructure for power distribution does not exist, is incredibly unreliable and/or very expensive. For a lot of these countries localised green energy generation is a key factor for development.

[ThomPete]

1) China uses everything they can from coal to nuclear to the wind. They are moving in ALL directions, not just one.

2) If you with green mean wind and solar then yes it means expensive because both have a low capacity factor and intermittency problems which means that either coal, gas, oil og nuclear have to be there as a backup. They, of course, need to be calculated in just as things like decommission which isn't being calculated in for wind and solar but is for nuclear. In other words, green cost as it's calculated is not the true cost.

3) No green isn't the most practical solution exactly for the reasons mentioned in 2). Sure you can provide a little here and there but you cant actually build a flourishing economy on wind and solar and there isn't a single example of that being the case. With oil, gas, coal and nuclear you can. Nuclear is too expensive which leaves us with fossil fuels.

So I would claim that your 3 reasons lack reality :)

[Brakenshire]

In the past, temperature rises caused by other factors have in turn caused the release of CO2, raising the temperature further. This does not in any way call into question the causality between increasing concentration of CO2 (a greenhouse gas) and increased warming as predicted by gas absorption equations which we teach in high school.

[flash_zombie]

> In the past, temperature rises caused by other factors have in turn caused the release of CO2, raising the temperature further.

That's your claim, but you can't actually derive that from the data. It may just as well be the case that rises in temperature cause the release of more CO2, period.

> This does not in any way call into question the causality between increasing concentration of CO2 (a greenhouse gas) and increased warming as predicted by gas absorption equations which we teach in high school.

The climate on the planet isn't a simple gas absorption equation, there are other factors. Even if the greenhouse effect is a factor, it couldn't be the dominating factor.

Otherwise, how could an ice age just "end" a period of high CO2 concentration? Shouldn't the greenhouse effect prevent it? And if so, will the next ice age be "tamer" if we keep CO2 levels up? Wouldn't that be good?