Elad Jelasko, Standard & Poor’s credit analyst: "The current structural changes in the thermal coal industry are not uniquely linked to climate change regulation, but result from the emergence of alternative cheaper energy in the U.S. Over the past two years, the price of thermal coal in the seaborne market has been steadily declining--to $75 per ton at present from $105 per ton in early 2012--which is putting pressure on a large part of the industry."

James Leaton, Research Director at the Carbon Tracker Initiative: "It is clear that already in today's market, the economics of exporting U.S. coal do not add up. Investors need to understand where we will see this kind of structural change in the coal market next"

Michael Wilkins, Head of environmental finance at Standard & Poor's: "Financial models that only rely on past performance and creditworthiness are an insufficient guide for investors. By analysing the potential impact of future carbon constraints driven by global climate change policies, our study shows a deterioration in the financial risk profiles for smaller oil companies that could lead to negative outlooks and downgrades. However, the effect on the majors would be more muted"

Simon Redmond, Director in S&P's oil and gas team: "Rating or outlook changes seem unlikely in the very near term, as the scenario is not materially different from the current price deck assumptions. However, as the price declines persist in our stress scenario of weaker oil demand, meaningful pressure could build on ratings. First the relatively focused, higher cost producers, and then also more diversified integrated players, as operating cash flows decline, weakening free cash flow and credit measures, and returns on investment become less certain and reserve replacement less robust."