Tall Tales

I was completely sane and sober when I wrote that line

But I do realise that it is counterintuitive and almost blasphemous.After all pollutants in the atmosphere cause ugly stuff like acid rain, smog, diseases and freak weather conditions ,among other things.And besides, for a post on Earth Day related to the environment this seems to be bordering on the sinful.

But before you  bring out the long knives and prepare to gut me out for being sensationalist, playing into the hands of Big Oil, denying climate change and murdering orphaned kittens take a look at this

Pictured: thousands of smokestacks running at full capacity

That- Mt. Pinatubo’s eruption in 1991- is some hardcore pollution. Oh, and it’s also completely natural.

Among its many effects, one was the cooling down of global temperatures.

Like cars and factory chimneys volcanoes release greenhouse gases like sulphur dioxide, carbon dioxide and water vapour in massive quantities.  Most of these end up in the troposphere, contributing to the greenhouse effect and climate change.

However, in certain cases, like the time during Mt. Pinatubo these gases actually end up higher in the stratosphere and exhibit  an opposite characteristic , cooling down the atmosphere.

Whoa, hold on. Stratos? Tropos? What the heck are these spheres? And why are these GHGs behaving like hormonal teenagers?

Glad you asked.

Atmosphere 101

While we were kids in school most of us studied a bit about the composition of the earth’s atmosphere and its various layers. To recap, the earth’s atmosphere is divided into

• Troposphere, starts from the surface and extends up to an altitude of approximately 20 km
• Stratosphere, starts from where troposphere ends and goes up to about 50 km
• Mesosphere, extends from stratosphere to about 80-85 km above the earth’s surface
• Thermosphere, which varies from 350-800 km above the surface of the earth
• Exosphere, which is virtually outer space and ends at around 10,000 km

Layers in the atmosphere, and temperature variations

As you may have guessed, troposphere, for us is the atmosphere. Weather events occur in this layer,planes fly here and  GHGs and particulate matter congregate in this layer.

This layer supports life on earth.

This layer is also where ‘climate change and greenhouse effect plays out.

Mt. Eyjafjallajökull and the troposphere’s tango

Incidentally, this layer, on top of the European landmass and Atlantic ocean has been  saturated with ash and smoke from the recent  Mt Eyjafjallajökull volcanic eruption.  This has resulted in an aviation nightmare, with tens of thousands of flights grounded and airports closed down for days. Even now, after several days of disruption the situation is nowhere near normal, as the volcano continues spewing smoke and ash.

However, as volcanic eruptions go, Mt. Eyjafjallajökull is small-fry. It does not compare  in any way with the massive Mt. Pinatubo eruption in Philippines in 1991 which ejected 10 cubic km of lava and cooled down global temperatures by 0.5°C.

And comparing it to the 1815 eruption of Mt. Tambora in Indonesia is like drawing comparisons between an ant and an elephant. That eruption, considered the most violent in recorded history spat out 100 cubic km of lava,killed off 10,000 people and transformed 1816 to a “Year without a  Summer”. It was a year which witnessed massive famines across Europe, America and Asia, freak weather conditions like snowstorms in summer and a cholera epidemic from Bengal to Moscow.

If the earth was a guy driving a car, Mt. Tambora was a sneeze so bad that he lost control, the car skidding off the road into a muddy ditch and turning turtle while he remained unconscious for two straight hours bleeding like a stuck pig.

The ditch represents the Year without a Summer

Greenhouse gases, massive volcanoes and hormonal teenagers

So why do GHGs released from massive volcanoes behave like hormonal teenagers, displaying apparently illogical behaviour?

Massive volcanoes, by their very definition eject smoke and gases with tremendous velocity into the atmosphere. In fact, this velocity is so high that most of the ejected material cross the tropopause and enter the stratosphere. There, sulphur dioxide combines with water vapour to form sulphuric acid in aerosol form (very tiny drops) which have a very high capacity to reflect back sunlight (science calls this high albedo).Therefore,less sunlight reaches the earth’s surface and accordingly temperatures go down.

Depending on the aerosol cloud this cooling effect could last for different periods of time,  also producing something called global dimming. The effects can last for up to two years, as in the case with Mt. Tambora.

Geo engineering and volcano mimicry

So if a Mt. Pinatubo can cool things down, is there any way we can  replicate its effects without the resultant lava and mass evacuation of people?Theoretically, we can, through geo-engineering.

Geo-engineering has both moral and technological challenges, and treating them would be out of the scope of this post.However there is no harm in exploring proof-of-concept ideas and doing some wild out-of -the box thinking.

Since global warming is blamed on the greenhouse effect, some scientists have suggested cooling down the atmosphere by mimicking the effect of massive volcanoes and injecting liquified sulphur dioxide into the stratosphere. Aerosol clouds will be formed, sunlight will be blocked and temperatures will come down.

An authority as noted as Paul “Dr. Ozone” Crutzen, who won the 1995 Nobel Prize in Chemistry for his work on ozone depletion believes that the only way to combat increasing temperatures would be to inject sulphur into the stratosphere,given how no one wants to cut back on emissions.

On a side note this statement,coming from him, seemed as unthinkable as Hitler waking up one fine morning and declaring that the Jews were valuable members of the German society or Bin Laden singing “The Star Spangled Banner” while saluting the American flag.

Even if the science behind sulphur injection is proven to be true, the real difficulty would be delivering the aerosol cloud at the precise altitude. While several expensive delivery techniques are being discussed, one very simple and relatively inexpensive delivery technique seems doable without any additional research.

It involves  an extremely light, 2 inches diameter hose about 18 miles long, sitting on a sulphur dioxide liquefaction plant and suspended by a series of helium balloons tied at regular intervals. Small swimming pool type pumps, but lighter would also be used at regular intervals to pump the liquefied gas up. A nozzle at the top will spray the liquid into the stratosphere and wind currents there would, in a matter of 10 days cover the entire stratosphere in a sort of a blanket, limiting sunlight.

This ingenious idea was featured in “Super Freakonomics” and has been proposed by a group of researchers and inventors in a think tank called Intellectual Ventures.

Ken Caldeira,an eminent environmental scientist associated with this concept has estimated that about 1,000, 000 tons of sulphur dioxide per year, or about 128 liters per minute would be needed to reverse the warming in Arctic and the Northern hemisphere. This is very less compared to the nearly 200 million tons of sulphur dioxode released by both natural events like volcanoes and human activities annually.

Also, since the effects of global warming are visible most strongly only at the poles, a few such hoses at the North and the South Pole should do the job effectively. As to the fears that this sulphuric acid would cause acid rain and deplete the ozone layer, there is another solution- monitor the effects and if they turn out to be harmful shut off the flow. The low quantities would not really cause long term and irreversible damages.

Solution to climate change

Geo-engineering experiments like injection of sulphur into the stratosphere are not the solution to AGW. The best  case scenario would be using geo-engineering as a complement to multiply the effectiveness of strategies like using clean fuels and reducing GHG emissions. They should never be seen as an excuse to adopt the status quo and keep dumping our refuse into the atmosphere.

For our collective sakes,the Earth deserves that from all of us.