Mention "renewables", and the response of many is that the future decline in fossil fuel resources will eventually drag the world into a more sustainable energy market structure, with some glitches on the way.

However, the reality is likely to be very different.

Globally, international oil companies and their equivalents in the state sector have access to enough oil and gas to keep production at close to current rates up to 2050, probably peaking around 2030, with currently uneconomic and other undiscovered resources still providing significant amount of fuel throughput into the next century. The world, including China, also has vast quantities of coal that remain untapped.

Globally, there is no rigorous regulatory and fiscal framework to create incentives for a radical departure in energy provision, which worldwide draws 80 percent from hydrocarbons, 7 percent from nuclear, 10 percent from biomass and 3 percent from solar, wind, hydro, tidal, wave and geothermal sources combined.

That last 13 percent, which we typically class as renewables, paints a checkered picture not only of the progress to date but also of where we are going.

Therefore, the challenge for the world, if it is to address carbon emissions urgently, is not merely the science-driven substitution of fossil fuels, it is managing the extraordinary commercial and geo-political issues of the inevitable disruptive change in the energy market that would result.

Carbon capture and storage (CCS) would be an essential component of an enduring oil, gas and coal industry. But if this becomes impracticable, the extreme scenario is that countries which rely almost entirely on hydrocarbon production for economic progress will have to be constrained through rigorously implemented international protocols. Injection of renewables into this market would have to have a sound commercial basis to be sustainable.

Confusing our decision-making is the uncertainty over just how significant climate change will be. That carbon dioxide in the atmosphere absorbs infra-red radiation from the surface of the Earth is not in question. This fundamental phenomenon has been recognized since the work of Swedish scientist Svante Arrhenius (1859-1927).

But, over the longer term, both the precise timing and magnitude of its effects are difficult to predict, because of the complexities of the real world.

Decision-makers rightly ask if we can be sure that billions of dollars are being budgeted in the right way.

As demand for energy increases in these uncertain circumstances, the gap between supply and demand will be filled, typically by what can be done most readily and cheaply: direct use of coal in power stations, and liquefaction and gasification for transport and heating.

Within Europe there will be a significant local energy deficit, and a number of countries have set their own targets for reducing emissions. For the UK, this will be a reduction of 80 percent by 2050 against 1990 levels; that is, to one-fifth of that historic level in a country presently even more dependent on fossil fuels than the global average.

The simple question then becomes: Do such countries continue to import fossil fuels with extensive CCS, or vigorously promote renewables, or both?

How much transformation, and even disruption, will society tolerate, and how can the next 40 years be projected as an extraordinary business opportunity?

Key to this is identifying the advantages of renewables more clearly and quantifiably. Full life-cycle analysis (LCA) is essential to show whether the areal yields for biofuels (the current maximum is 4 tons per hectare per annum, in Brazil) do, indeed, stack up against the carbon dioxide disbenefits of land clearance, fertilizer usage, production and distribution costs. Even with this yield, one-quarter of the UK land mass would be needed to power just the country's passenger cars. High-yield options, including genetic modification, are being considered for a viable future in this sector.

Solar devices capture 50 to 100 times more energy, area-for-area, than biofuel farms. Costs are currently relatively high, but the technology is advanced, the problem is that the world is unused to a society where electricity for power, transport and heating is all-pervasive. Storage of this electricity (and derived hydrogen through electrolysis of water) is the key challenge.

It will require enlightened engagement between science, engineering, politics, business and customers to make bold evidence-based decisions to take us, with global and national leadership, to a new and sustainable future.

The author is chief executive of the Royal Society of Chemistry in the UK.