The age of wind and solar is here

That day will come, the life-changing moment when renewable energy — wind, solar, geothermal and others still in development —replace fossil fuels as the principal source of world energy.

Most analysts insist, however, that this day will not arrive for many decades to come, reports Scientificamerican.com. Fossil fuels are too entrenched, it is said, and renewables too costly or impractical to usurp existing systems. According to the International Energy Agency (IEA), the share of global energy provided by renewables — a mere 14 per cent in 2012 — will increase only slightly between now and 2040 — 19 per cent.

Cleaner energy, sooner

But there are good reasons to believe that the transition to renewables will occur much faster than previously ass-umed, pushing that percentage higher and higher. Indeed, recent increases in wind and solar installations have been running at nearly twice the rate of the IEA’s projections for long-term capacity growth, suggesting that its projections of renewables’ share of global energy are much too low.

Any new form of energy initially operates at a severe disadvantage, lacking the elaborate production, processing and distribution networks retained by the prevailing type; before it can overcome that disadvantage and become the new leader the upstart must create a duplicate infrastructure — something that typically requires many decades. It took more than 50 years for coal to replace wood as the world’s leading source of energy and another 50 years for oil to overtake coal.

Extraordinary time, extraordinary measures

The growing concern over climate change is leading to strict controls on carbon dioxide and other greenhouse gas (GHG) emissions, while a continuing cascade of innovations in renewables technology is lowering their price and speeding their installation.

In a 2009 Scientific American cover story, Stanford University engineering professor Mark Jacobson had presented a plan showing how the entire world could be powered by wind, solar and water sources by 2030.

There are, of course, many obstacles to the effective control of carbon emissions, as demonstrated by the unremitting efforts of US coal companies and their congressional allies to block the imposition of new ru-les by the US Environmental Protection Agency (EPA). Nevertheless, it is impossible to dismiss the progress being made at the local and international levels to curb GHGs and promote the use of renewables.

The European Union, for example, is well on the way to achieving a 20 per cent reduction in GHG emissions from 1990 levels by 2020, along with a 20 per cent increase in the share of its energy obtained from renewables. In the US upgraded fuel-efficiency standards for cars and light vehicles will reduce US consumption by an estimated savings of 12 billion barrels over the next 10 years. And China, the world’s leading fossil fuel consumer, has pledged to cap the growth in its carbon emissions by 2030.

Despite such progress, it appears unlikely that the world will succeed in preventing the expected increase in global temperatures from exceeding 2 degrees Celsius, the maximum amount, most scientists agree, that the Earth can absorb without experiencing catastrophic climate events.