They are not valid arguments against climate change being man-made. It's all simply continually mis-represented science pamphleted by those who either do not know enough to be making public announcements or refuse to acknowledge a problem and twist data to suit their own ends."Most of the observed increase in global average temperatures since the mid-20th century is very likely [>90% certainty] due to the observed increase in anthropogenic greenhouse gas concentrations."
Yes Earth does have cycles of warming and cooling, but the current climatic trends do not fit with any of them. In fact, if we were following normal cyclic patterns, we would be entering a colder period at the moment, not a warmer one.
I haven't studied the most recent deglaciation so I don't know why it ended specifically in that case, but we have had many periods of glaciation in Earth's history, and they go through periods of waxing and waning due to concentrations of atmospheric gases, changes in solar activity, changes in land use, changes in land formation, and much more. There are many natural reasons for an ice age to draw to an end, and no it wasn't due to land rovers (I can safely assume that!). As with my previous comment, this period should not be warming up, it should be cooling down.
I don't know about scientists recording temperatures on other planets, so I can't comment on this. However, firstly: how are they recording the temperatures? Because if they are doing it via telescope then they are not recording present day temperatures and the data is irrelevant to modern day climate change. Secondly, we know the sun is getting hotter. Stars get "brighter" over their lifetimes. However solar intensity can not account for the temperature increases over the last few decades, simply because it does not happen quickly enough.
Tim Ball's quote is not an argument against human-induced climate change. It's simply an acknowledgement that the climate does change (which no one is denying). Secondly, we do not live in a world where the minority overrule the majority in matters of science. One scientist saying that climate change is not due to human activity doesn't mean the other 1000+ scientists that say it does are wrong. Most likely, the one scientist whose arguments are contrary to everyone else's is in the wrong.
Volcanoes are not causing climate change, if that is what you are suggesting. They affect weather (short term atmospheric activity - climate is like the long term average of weather, if you like), at most of a period of months or a couple of years and except in exceptional cases they are regional disturbances (not global). An example would be Mount Pinatubo in 1991, which incidentally cooled temperatures the following year - it didn't cause warming. The general trend is that volcanic eruptions cool the Earth (depending on many factors that I can't be arsed to explain, and which would make a whole other reply really. lol. But basically type of eruption and size of eruption are important if you want to measurably change the weather).
Regarding their CO2 output, climate change deniers always forget to mention that volcanoes also remove CO2 from the atmosphere, and that the net balance of their activities is 0.
If only 5% of CO2 is from man-made sources, thats still 5% more than Earth would have if we weren't doing anything. Earth might be large but there are a lot of delicate systems working to keep things ticking over smoothly and everything is balance. CO2 (and most greenhouse gases) can do a lot of damage in very small relative concentrations. It's kind of like comparing salt with arsonic. A small amount of salt will do very little to you, while the same amount of arsonic will kill you instantly. The amount of CO2 in the atmosphere that was put there by us does not matter if it is more than the system can cope with. CO2 levels are now higher than they have been in Earth's atmosphere for at least the last 500 000 years. If you go over the white line the middle of the road and hit an oncoming car you are still the cause of the accident whether you are over the divider by a foot or an entire car's width.
You don't need a computer model for predicting warm/cool periods as such. You simply input the data from the last 6 million years (or whatever other time you want to study) and extrapolate. For general Earth variations there is consensus on what should happen. It's only conjecture in the sense that it assumes what has happened over X amount of years (whatever the initial data set size is) will happen in the future.
I wouldn't say all media sources are claiming we are cooling. We most certainly are not. One study, which incidentally says temperatures have been flatlining since 2001 and therefore isn't long-term enough to prove that the climate is cooling, does not mean that scientists are now disregarding global warming. Scientists cannot control what the media (and by that leap the public) choose to repeat: just because the press have jumped on an idea ("jumped on the bandwagon") does not mean those with the knowledge in that field are doing the same. Incidentally, I shall just clear this matter up because it really pees me off (my mother likes to say it to wind me up): Global Warming does not mean that everything gets hotter and tropical. It means the global trend is an increase in temperature. It actually exasberates mid-latitude climates, so North America and England should be seeing harsher winters and more variable summers (which for Britain at least, we have done). An easy way to think of it is like this: Global Warming simply exaggerates whatever weather that country already had.
I seriously doubt the statement that grant funds disappear unless you say alarmist things about the climate, or at least doubt that it is happening on a large enough scale to be producing measurable results. Even if some people are pulling the plug on funding if it isn't newsworthy, there are many many many establishments out there funding research and not even the Wall Street Journal can accuse every single funding body of trying to propogate alarmist science. Also science is a peer-review subject, so even if a few scientists being funded by "rogue bodies" are promoting illegitimate scientific research, it would be shot down in the science journals by colleagues who recognised the bogus science, and thus it wouldn't gain credence (unless a dodgy journalist decided to write about it in his weekly magazine, and conveniently "forgot" to discuss what the peers were saying on the matter).
Christopher Booker is a known Climate change denier and therefore the last journalist likely to be presenting a scientifically-sound argument against climate change (some of his "facts" in previous columns have actually be denied by the sources he claimed to have got them from). Also, as I said re: "the media say we are cooling" paragraph above, we shouldn't be seeing milder winters. We should be seeing more extremes. So our crap winter is technically further proof that our climate is changing. Also, this is not an argument against man-made climate change, it is an argument against global warming. I thought you weren't denying that Earth is getting warmer? Because if you are denying that too, that's a whole other kettle of fish! I don't think there is a scientist left in the world that would deny that the datasets prove that temperatures are increasing. Regarding the Met Office predicting it would be a mild winter, that simply shows how poor we are at predicting the weather. No one is denying that! Though, I would wonder why the Met Office predicted that, when my supervisors at uni and most my fellow graduates could probably have told them that was unlikely, given what a bad summer we'd had.
"If they can't predict what is going to happen in a few months how the flip do they know what will happen in years to come?"
Predicting what will happen years down the road is "easier" than predicting what will happen in a few months. This goes back to the difference between weather and climate, which I briefly touched on earlier. Weather is dependant on a lot of atmospheric processes that we don't fully understand, or in some cases don't understand at all. The climate is dependant on long term factors such as solar intensity etc., and these are more cyclical in their nature and therefore easier to predict (all except human activity of course, which is not cyclical. Future predictions on human activity are done by extrapolating present-day activity and predicting things that I don't understand. I think that is done by futurists and industrialists).
I think I shall finish on a quote from the most recent IPCC assessment, which is done by hundreds of the world's leading experts on climate change (you can read the reports yourself on their website, but I warn you that they are very long!):