Climate change is accelerating. We have already crossed the threshold of the carbon dioxide concentration in the atmosphere of 400 parts per million. Atmospheric CO2 is warming our planet and acidifying the water. Something has to be done. Lima Call for Climate Action represents a good platform for future response to greenhouse gas pollution. As Ed Davey, UK’s secretary for energy and climate change said, “for the first time ever the world can contemplate a global deal applicable to all.”

Although world leaders have finally responded to countless alerts of the scientific community and took a tougher line in combating global warming, it may be too late to hamper the effects of the unchecked abuse we have done to mother nature. Our only remaining hope might be geoengineering, the technology that has been so far considered as the last resort for the world’s salvation. But, what can actually be done, and what could be the consequences of our deliberate manipulation of the environment?

Possible solutions are mainly based on two approaches: those which aim towards the reduction of greenhouse gases, and those devising different plans to block the sunlight in order to cool the planet, know as solar radiation management (SRM). Some have even gone so far to suggest we should resort to human engineering in order for our bodies to reduce carbon emissions. Many of the quick fixes proposed so far can have the unforseeable consequences, that threaten to make the solution worse than a current problem. Computer models have shown that the most promising models from the standing point of their effectiveness, also have potentially devastating ramifications to large portions of humanity, and should really only be used as a last resort.

Capturing, storing and depositing carbon dioxide
These techniques are also known as carbon sequestration. They include a variety of methods for trapping industrial CO2 emissions or removing it from the atmosphere with giant sucking filters and depositing it in large subsurface reservoirs. All these solutions are costly, demand huge infrastructural undertakings that would last for decades to deploy, and would amount to more than what we would ‘loose’ if we choose to limit our economic growth. Captured CO2 would have to be stored under strict conditions in order to avoid potential rapid releases, which could be lethal to any life-form in the vicinity.

Lohafex experiment of iron fertilization from 2009, comprising of depositing six tons of iron solution into the ocean as a way to boost blooming of phytoplankton that can trap large amounts of carbon from the atmosphere inside their bodies, showed limited success.

One of the potential solutions to tackle climate change envisions planes spraying sulfate aerosols into the stratosphere to mimic the effect of volcanic eruptions. It could reduce the global temperature and give us a breathing space, until we develop a more stable solution. The side effects could be ozone depletion and the reduction of rainfalls , since these settings would absorb some of the heat from the planet’s surface, and alter the water cycle, thus depriving some parts of the world, especially the tropics, of regular rainfalls.
Cloud brightening, or to use that fancy expression – cloud reflectivity modification (sounds savvy), seems better solution, since this process is thought to be easily reversible and would not have any lasting negative consequences to the overall climate, since its effects last only a couple of days. It consists of spraying aerosols of sea water into the atmosphere to increase albedo (reflection coefficient) of clouds, observed as cloud whiteness. Special, remotely controlled, unmanned ships would patrol the oceans and spray sea water into the sky to crate additional clouds, thus increasing the reflective shield over the oceans.

Dr Roger Angel from the University of Arizona thinks a 100, 000 square mile sunshade made of trillions of mirrors, deployed million miles above Earth and synchronized with Earth’s orbital period could shield our planet from the Sun’s radiation for centuries. It would reduce some 1.8% of solar energy traveling in our direction. That such idea is not so outlandish, proves the fact that the study was funded by NASA.
Since global efforts to tackle the problem of global warming are caught between economic sustainability and responsible management of resources, without any concrete solution on the horizon, SRM has gained popularity in recent years. A profusely funded Solar Radiation Management Governance Initiative (SRMGI) is a global network, a result of a partnership of The World Academy of Sciences (TWAS), the Royal Society, and the Environmental Defense Fund (EDF) which mission is to search for solutions to “rapidly reduce rising global temperatures.”

Unfortunately or not, none of these methods can provide a permanent solution for our greenhouse planet, and can have unfathomable adverse consequences. Now that the natural equilibrium has been disrupted, we are running out of options. People are prone to say, “No” beforehand to every idea involving the word ‘engineering’ in combination with ‘geo’ and ‘bio’, but, we better do something, anything, before we reach the point of no return! Remember prophetic lines from Pink Floyd album Division Bells “She (Nature) can take it back, she will take it back some day.”