Scientists recently published a paper in Proceedings of the National Academy of Sciences of the Unites States of America. Wang et. al., (2014) claim that increasing levels of pollutants in Asia are intensifying storms in that region.
On the surface of it, a cheer might go up from the anti anthropogenic global warming crowd as it’s not exactly burning fossil fuels here. After all, only last year, the cry went out that storms were becoming more extreme in Asia after the Philippines were hammered by Typhoon Haiyen.
But let’s stop and think about this for a minute… Everyone with access to the internet now, has probably seen pictures of China with smog so thick you can barely see the building across the street. It may get smoggy in valley cities like Los Angeles, USA or Santiago, Chile, but the smog seen in China is on a whole new level! Having flown over China quite a few times, that smog may be at its densest in areas that favour atmospheric inversions like Beijing, but the pollution in China covers most of the country, albeit, in most parts, its just more hazy and not sky-blocking.
Last year, NASA released a photograph showing that the smog is visible from space. Now, it might be safe to say that image is only showing an area over Beijng – but that is an area containing pollution (why don’t they ever put scale bars on pictures anymore?!) that covers approximately 100 square miles of pollutants all blowing out into the Pacific Ocean and into the path of storm systems.
So why would these particles in China’s pollution be causing stronger storms? Let’s ask some questions:
When do typhoons form?
From reading anecdotal information online (ie is the smog seasonal in China?), it would appear that the smog is at ‘lowest’ in late summer/early fall. Typhoons may happen any time in the year, but most common in summer. So conservatively, you could be looking at 10 months of the year with bad smog drifting into the Pacific. How long does it take for the smog to get to the areas of big storms? I don’t know – no easy answer out there on the web… But we do know its been drifting out pretty steadily for a number of years now.
How do typhoons form?
Broadly speaking, you need the following: sufficiently warm sea surface temperatures, atmospheric instability, high humidity in the lower to middle levels of the troposphere, enough Coriolis force to develop a low pressure center, a pre-existing low level focus or disturbance, and low vertical wind shear.
How does rain form?
Most rain is believed to form from water coalescing on an ice crystal or dust. Remember, one of the ways people want to geoengineer is to ‘seed‘ the atmosphere with inactive ‘dust’ particle to cause more clouds which in turn, in theory, would reflect more heat back into space. As this was proposed as a way for China to reduce its pollution, it’s kind of ironic it is doing it anyway, and might lead back into stronger storms, not calmer ones as was proposed in 2012…
What makes up the Chinese smog?
There are a number of factors which contribute to the smog in China, including deforestation to the west, the explosive growth in cars on the road, the equally explosive growth of industry, energy derived from coal (and some of the ‘dirtiest’ coal out there), people burning coal to keep warm in winter… In summary, the rather explosive growth of the country is causing the smog.
However, before anyone jumps up and down and says Los Angeles has come a long way in controlling its smog, so all China has to do is tighten up its pollution laws, do bear in mind, the explosion in growth has come very rapidly (last 10 years) and sources of energy have not kept pace with growth (ie still a heavy reliance on coal). I don’t doubt China is making many silly mistakes where they could have learned from the west, but at the same time, they are still frantically trying to catch up and transition away from energy sources like coal.
Which brings me full circle to concluding that actually… China burning fossil fuel and the particulates that go into the atmosphere as a result IS probably contributing to additional rain/cloud and MAY be causing stronger storms as a result. It may not be the usual target for the antropogenic warming crowd – burning fossil fuels releases CO2 which is causing global warming – but the burning of excessive amounts of fossil fuel is producing a considerably larger than normal amount of air particulates which is trapped by the pollution-trapping geography of Beijing before being blown out to the storm factories in the Pacific ocean by weather systems.
However, that said, there are still a number of questions to be answered, including why haven’t there been more strong storms in the last decade? And if we removed the smog from the equations in the climate modelling of Wang et.al (2014), will there by any measurable reduction in stronger storms?
It’s not nice to think China’s pollution woes are causing health issues in China and physical destruction by nature elsewhere, but it still may not be enough to significantly increase the intensity of storms. However, the serious health issues for all living things who live within the realm of that smog should be more than enough incentive to try and reduce China’s smog!