Carbon bubble could fuel another global economic crisis, report warns The research has been conducted by Lord Stern, a professor at the London School of Economics, and think tank Carbon Tracker, which is supported by HSBC, Standard & Poor's and the International Energy Agency, among others. Stern found that the top 200 firms spent $674bn (£441bn) - equivalent to 1pc of global GDP - last year to find new resources, which may not be harvested. "The scale of "listed" unburnable carbon revealed in this report is astonishing," said Paul Spedding, an oil and gas analyst at HSBC. " This report makes it clear that "business as usual" is not a viable option for the fossil fuel industry in the long term. [The market] is assuming it will get an early warning, but my worry is that things often happen suddenly in the oil and gas sector. Up to 60pc of the market capitalisation of oil and gas firms is at risk from the "carbon bubble," HSBC concluded. Governments have agreed to cap any rise in global temperatures to 2C, but Stern argued that investors "can't believe that." Ratings agencies have also expressed concerns, with S&P stating that the risk could lead to oil companies being downgraded within the next few years. Lord Stern said the risk was "very big indeed," adding: "The financial crisis has shown what happens when risks accumulate unnoticed."