Some rather controversial views on fossil fuel usage – not just as a fuel – and particularly on carbon capture; it makes depressing reading

The most powerful leaders in the West used the G7 summit in Germany to make a big statement on the environment. Their stated goal is to cut carbon emissions by 40% to 70% by 2050 and then end all fossil-fuel use by 2100. They announced a US$100bn (£65bn) fund by 2020 comprising public and private money to help smooth the transition. My response to David Cameron, Angela Merkel and the rest is pretty simple: good luck with that.

When people talk about decarbonisation, they tend to make the mistake of thinking about energy only in terms of electricity. If you ask how to wean us from fossil fuels, they will say build more solar power, more wind farms and so forth. There are several problems with this. We are already struggling with capacity on the grid and have a huge task to add as much renewable energy as it can cope with. To cover the extra requirements to make heat and domestic transport electric, we would need five times more. I don’t know anyone who thinks this is remotely realistic.

Because most forms of renewable energy only work when the power source is available, be it wind, sun or whatever, we will need large amounts of storage capability to allow them to replace electricity powered by fossil fuels. And while it’s easy to see how you can store kilowatts and megawatts of green power in the batteries of the future, getting up to gigawatts is another matter. The huge engineering requirement makes it almost impossible to get the costs to a point where this is viable.

Electricity is also the least of the big drains on energy. The big challenges are transport fuels, especially for long-distance haulage and trans-ocean shipping. We really don’t have any smart ideas for replacing diesel for these yet, and it’s difficult to see where they will come from. The Royal Academy of Engineering did a study in 2013 looking at the options for low-carbon fuelling of shipping. The best it could come up with was LNG (liquefied natural gas).

You can conceive of running large numbers of domestic cars on green electricity by charging them on the grid. But the idea that anybody is going to be able to produce a battery big enough to store the electricity to power a passenger aircraft or a major container ship is laughable.

Read more: The Conversation