Few things should make you as optimistic — or as pessimistic — as the rise of renewable energy. Optimism comes from a new sense of urgency as the UK, Germany and Spain set record highs for use of wind and solar power, and record lows for coal. Even the US can now generate more power from renewables than from coal, and last month, the “Ocean Wind” project in New Jersey was the largest ever offshore wind farm procured by a US state.

Yet pessimism comes from the fact that all of this may not be enough. In our research at UBS, we estimate that to avoid a dangerous level of global warming, the world would need to commission an asset the size of New Jersey’s Ocean Wind every day for the next 30 years, without missing a day. Or put another way: we need to triple wind and solar construction overnight and sustain that new growth rate for decades, with no room for setbacks.

The hard truth is that we are not on track for that. Nor are we close to an overnight technical solution to the many other challenges of the energy transition that must be solved before we can develop a 100 per cent clean energy system.