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Isoprene: Struggling for Air

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Climate change is one of the most important reasons to improve science communication. Solid communication is the only way to keep those that think that our
changing climate is a hoax, fabricated into an elaborate web by scientists and high ranking government officials. My first retort to this, is that it would be impossible to have every scientist in the world on the same page, it’s hard enough to get me and my supervisory team in the same room, at the same time, let alone organise a global conspiracy. The second thought is, government would actually have to listen to us. But that is a topic for another day…

As things stand, climate change is probably our strongest topic when it comes to communication, however, it is still failing. I’m sure if you asked any member of the public what they know about climate change, they would reply with a handful of buzzwords:

“Carbon Dioxide, Global Warming, Melting Ice Caps, Renewable Energy” - Every Member of the Public.



Where this level of education is good, and doesn’t occur in other fields of science it’s still not enough. There are so many things that not just the public are yet to grasp, but government and other scientists too. Recently, I was one of these ‘other scientists’ at a conference day dedicated to the subject of another climate changing gas, Isoprene.

Isoprene and Ozone

Isoprene is a gas that is produced naturally by plants and bacteria, as well as everyones favourite marine group of organisms phytoplankton. When it is released, usually via leaves in higher plants such as conifer trees, it’s highly reactive. Therein lies the problem.

I’m sure everyone reading is familiar with the concept of the ozone layer. Lots of compounds that were previously released, such as CFCs (who’s release was later fixed by the famous
Montreal Protocol), reacted with the ozone layer, breaking it down and exposing us to greater levels of harmful UV radiation. Isoprene works in a similar fashion, but generates low level tropospheric ozone, while it breaks down other compounds present in the atmosphere due to its high reactivity.

“So Isoprene is making ozone? Surely that’s a good thing?” I hear you ask. Well, in short, not really.

The production of low level ozone, which is in fact harmful to respiratory systems, also increases the residence time of other potentially harmful biological compounds. The chemistry of this is quite complex, and depends on - and is further complicated by - the different compounds that it is breaking down.

Isoprene and Climate Change

But what does this mean for our changing climate? How does that effect isoprene? Will it increase the effects or counteract them? Well in terms of long term effects, we are not sure.
However, what we do know, is that there seems to be an
inverse relationship between CO2 emissions and isoprene emissions. Which basically means that as CO2 emissions increase, isoprene release is inhibited.

This does not necessarily mean that the threat of isoprene is counteracted by our burning of fossil fuels. Currently, there is a lot of pressure on governments to move to greener energy sources, such as
biofuels.

And there in lies the real threat of isoprene. Unfortunately for us common plants that we are growing in extortionate numbers, are, you guessed it, massive isoprene producers. Take palm olive trees in the tropics. Their coverage is expanding almost exponentially in attempts to combat our ever rising CO
2 emissions, and is in fact causing larger levels of isoprene emissions and therefore formation of harmful low level tropospheric ozone.

There are political impacts as well. Europe’s air quality is governed by an EU directive, to keep low level ozone below a certain threshold. If plans go ahead to increase the plantation of biofuels across mainland Europe, the increase in ozone levels would take us over that threshold, opening us up to fines from the EU.

The Way Forward

So how do we move on from this? How to we begin to combat gas emissions on multiple fronts? Let’s just say isoprene isn’t the only gas people don’t know about.
Well, if it puts your mind at rest, know that there is a lot of research going into isoprene in the scientific community at present. Experiments have been running silently, looking into the exact way in which organisms produce and break down isoprene, to attempt to genetically modify biofuel crops to enhance it’s breakdown and therefore lower emissions. Solving the issue of air quality while simultaneously allowing expansion into the biofuel arena.
There are also plans to build a chamber, which effectively acts as a breathalyser for plants, monitoring exactly what gases they release and under what conditions.

It’s still very early in the investigative timeline for isoprene, but already there are some very interesting implications for a very complicated gas. In short, watch this space, and stay informed!



Seth Author