Engineering Dynamics Expert Hugh Hunt Explores The Viability of Climate Engineering and 'Block Out The Sun' As A Way To Cool Down The Earth and Depleting Carbon Emissions

The United Nations Climate Change Conference in Paris is underway and all set for December. At that gathering of world leaders, many expect the lobbying of an agreement to cut down carbon emissions worldwide. However, Hugh Hunt, a Reader in Engineering Dynamics at the University of Cambridge, is saying that "emissions cuts alone may not be enough."

In a CNN report published Nov. 19, Hunt explores various methods to ease out the effects of climate change so as to protect the world's economy and avoid an upsurge of crises.

A suggestion, although wildly controversial, is coming up in the name of Solar Radiation Management (SRM). While the name sounds fancy, what it basically does is reflect some of the sun's energy back into outer space. This climate engineering mechanism would, as a result, cool our planet down.

One way of achieving this is by spraying sea water up out of our oceans to form clouds, reflecting back the sun's heat.

Another way of SRM could work is by putting mirrors at the point between the Earth and the Sun where gravity is most balanced. The mirrors could reflect at least 2% of the sun's rays back to space, but for a hefty price tag.

Finally, Hunt proposes a more natural approach: spraying particles up into the stratosphere. Similar to a large volcanic eruption, the particle injected into the atmosphere at high altitude could cool the planet.

"We know from large volcanic eruptions that particles injected at high altitude cool the planet," Hunt says, adding that the eruption of Mount Pinatubo in the Philippines in 1991 is the best example in recent times.

"It is estimated that more than 10 million tonnes of sulphur dioxide were propelled into the high atmosphere and it quickly formed tiny droplets of sulphuric acid - yes, the same stuff found in acid rain - which reflected sunlight and caused global cooling."

However, Hunt admits blocking out the sun's rays is not a "quick fix" and that climate engineering can cause big environmental problems as well, such as acidification of oceans. It is certainly not, Hunt says, a "get-out clause".

Nevertheless, Hunt emphasizes the need to deplete the 600 billion tons of fossil carbon that we've emitted into the air in the last 250 years.