I really should know better than to discuss my job in public. Admitting to being a climate scientist tends to result in lengthy discussions of why we are told to reduce our carbon footprint when it’s developing nations that are “the problem”, why we think we can predict the climate in 100 years time when “tomorrow’s weather forecast is wrong”, and more recently defending our scientific integrity.

In fact there isn’t a typical “climate scientist” (leaving aside the generic “scientist” with his grey beard, white coat, socks and sandals that is!). Every one of my colleagues works in a very different way towards understanding the building blocks of our atmosphere and oceans and how changes in these affect day-to-day weather and year-to-year climate. My work concerns how particles in the atmosphere affect the way in which radiation from the sun reaches the ground. These “aerosols” are very small droplets of dissolved sulphate and nitrate chemicals and specks of soot from fossil fuel burning, desert dust picked up by Saharan winds, microscopic debris from volcanic eruptions and even sea salt from bursting bubbles on the ocean surface. One hundred times smaller than the droplets you might spray from an aerosol can, each one of these tiny particles suspended in the air has the potential to scatter or absorb radiation from the sun, preventing it from reaching the Earth’s surface and therefore potentially cooling the ground. Some of them can also attract enough water to spark the growth of cloud droplets – indeed without them it would take so long for enough water molecules to get together and grow that we’d never see clouds at all!

I fly through pollution plumes in the Facility for Airborne Atmospheric Measurement BAE146 aircraft. In recent years colleagues and I have measured aerosols from European pollution, African biomass burning and desert dust, and volcanic ash. Once I know how big the particles are and what they are made of, I use computer simulations of sunlight bouncing off them to calculate how much of the suns light is prevented from reaching the surface. I can also tell colleagues what characteristics they should give these particles in their global climate model so that they can simulate their impact on climate change. If I venture to the coffee room I can learn about glacier melt, ocean current modelling, how to extract useful data from satellite instruments, the physics of hurricanes, the impact of road transport or supervolcanoes on surface temperature, or changes in African rainfall over the past decades. Other colleagues will be in laboratories, recreating constituents of our atmosphere or ocean in a controlled environment, while still more will actually be out in the weather making observations of atmosphere, ocean, land or ice. There are so many exciting ways of probing our earth-atmosphere system, but whichever one an individual climate scientist chooses, we all have the same goal – to understand the processes that make up our earth-ocean-atmosphere system. This will help to improve the quality of those climate (and weather) predictions.

So, I think overall I’m proud to say that I am a climate scientist. It’s just as well really, my only other option is to say that I am a physicist and that tends to result in a glazed expression and an abrupt end to the conversation. Hmm…. wait a minute, that could be useful…..

This article was originally published in theWeather magazine of the Royal Meteorological Society in 2010