Citi report: slowing global warming would save tens of trillions of dollars | Dana Nuccitelli

A report from America's 3rd-largest bank asks why we're not transitioning to a low-carbon economy

Citi Global Perspectives & Solutions (GPS), a division within Citibank (America's third-largest bank), recently published a report looking at the economic costs and benefits of a low-carbon future. The report considered two scenarios: "Inaction," which involves continuing on a business-as-usual path, and Action scenario which involves transitioning to a low-carbon energy mix.

One of the most interesting findings in the report is that the investment costs for the two scenarios are almost identical. In fact, because of savings due to reduced fuel costs and increased energy efficiency, the Action scenario is actually a bit cheaper than the Inaction scenario.

What is perhaps most surprising is that looking at the potential total spend on energy over the next quarter century, on an undiscounted basis the cost of following a low carbon route at $190.2 trillion is actually cheaper than our 'Inaction' scenario at $192 trillion. This, as we examine in this chapter, is due to the rapidly falling costs of renewables, which combined with lower fuel usage from energy efficiency investments actually result in significantly lower long term fuel bill. Yes, we have to invest more in the early years, but we potentially save later, not to mention the liabilities of climate change that we potentially avoid.

By comparing the cost of mitigation to the avoided 'liabilities' of climate change, we can derive a simple 'return on investment'. On a risk adjusted basis this implies a return of 1-4% at the low point in 2021, rising to between 3% and 10% by 2035.

With a limited differential in the total bill of Action vs Inaction (in fact a saving on an undiscounted basis), potentially enormous liabilities avoided and the simple fact that cleaner air must be preferable to pollution, a very strong "Why would you not?" argument regarding action on climate change begins to form " Coupled with the fact the total spend is similar under both action and inaction, yet the potential liabilities of inaction are enormous, it is hard to argue against a path of action.

The clear loser between the scenarios is coal, which sees its total investment bill fall by some $11.5 trillion over the next quarter century. Gas investment also reduces though by a far smaller amount, $3.4 trillion in total

Some studies suggest that globally a third of oil reserves, half of gas reserves and over 80% of current coal reserves would have to remain unused from 2010 to 2050 in order to have a chance of meeting the 2C target.

Paris offers a generational opportunity; one that we believe should be firmly grasped with both hands.