Business Green: Although annual global expenditure on renewable energy projects is expected to jump from $90bn (£59bn) last year to $150bn by 2020, it will need to increase by up to a third more if the world is to avoid dangerous levels of climate change. That is the conclusion of new research released this week by Bloomberg New Energy Finance, an analyst firm specialising in renewable energy and carbon markets, which warned yearly investment in renewable power sources must rise to $230bn by the end …