One of the best things about the Internet is the way it lets ideas be hammered out, if only for the benefit of the people who follow the hammering. (Note: the fact that insane Internet conspiracy theories seem to do rather better than hard facts is of course a problem.)

Take this really good analysis by Tim Worstall, swiping at Richard Murphy’s claim that it is not possible to deal with Climate Change while growing global economic output significantly in the coming century.

Tim takes the trouble to break down a number of complicated issues into bite-size chunks which we lesser mortals might understand. Well worth a look.

He surely is on to something important in peeling away at rival scenarios for the impact of climate change. Since the likely damage (and benefit) caused by global warming depends in part on how and where people are living in decades to come, which in turn requires us to make intelligent assumptions including about economic growth.

At the very heart of the policy on all this is the famous Social Discount Rate. In essence, if the planet is likely to grow quite a lot wealthier in the decades to come, should people now subsidise people a century hence?

Would it have made sense for people in 1907 to make significant economic sacrifices for the benefit of people alive now? Not obviously – they were far poorer then than we are, and the uncertainty of the future would have led to serious mistakes in the form of sacrifice taken.

Which is why some experts say that even if we all agree that climate change is a Problem, the wisest thing to do is probably not very much – rather than scramble around spending huge sums of money now trying to fix long-term trends, much more effective to spend money in the future to deal with specific problems as they arise.

See eg Bjorn Lomborg:

Likewise, reasonable people can differ on their interpretation of the Waxman-Markey bill. Even if we set aside its masses of pork-barrel spending, and analyses that show it may allow more emissions in the US for the first decades, there are more fundamental problems with this legislation.

At a cost of hundreds of billions of dollars annually, it will have virtually no impact on climate change. If all of the bill’s many provisions were entirely fulfilled, economic models show that it would reduce the temperature by the end of the century by 0.11°C (0.2°F) – reducing warming by less than 4%.

Even if every Kyoto-obligated country passed its own, duplicate Waxman-Markey bills – which is implausible and would incur significantly higher costs – the global reduction would amount to just 0.22°C (0.35°F) by the end of this century. The reduction in global temperature would not be measurable in a hundred years, yet the cost would be significant and payable now.

Is it really treason against the planet to express some skepticism about whether this is the right way forward?

And while Tim is at it, he demolishes a scary Oxfam claim that climate change is going to flood the world with 75,000,000 economic migrants by 2050. He simply runs some elementary maths over the arguments and cuts them down to their puny size.

Inconvenient truths.