ESA Releases Bad and Good News from Earth's Atmosphere Studies

Carbon dioxide emissions increased in East Asia (right) at an average rate of 9.8% per year from 2003 to 2011, but nitrogen oxides increased by ‘only’ 5.8% per year.  

This indicates a use of cleaner technology in East Asia. 

North America and Europe, however, show slightly decreasing trends for both gases. 

The maps show the corresponding spatial pattern as obtained from the satellite data: red corresponds to regions with high values of NOx and CO2, while blue indicates background values.

Credit: ESA

While Europe and North America show a decrease in emission trends between 2003 and 2011, emissions related to economic growth in East Asia continue to rise, but with a reduction in nitrogen oxides emitted per amount of carbon dioxide.

This demonstrates the use of cleaner technology in East Asia.

Nitrogen oxides are generated during the high-temperature combustion of fossil fuels in automobiles and industrial machinery.

They contribute significantly to a reduction of air quality and can be the cause of respiratory problems.

At the same time, these sources release large amounts of carbon dioxide. Carbon dioxide is toxic only at very high concentrations, but is the most important man-made greenhouse gas, leading to global warming and its related consequences.

In a study published yesterday in Nature Geoscience, scientists from the University of Bremen in Germany used data from the Sciamachy instrument on ESA’s Envisat satellite to measure nitrogen dioxide and carbon dioxide trends from 2003 to 2011.

They also exploited  Sciamachy-based data products generated within the ‘GHG-CCI’ project under ESA’s Climate Change Initiative.

“Nitrogen dioxide has a relatively short lifetime, hours, compared to carbon dioxide, which lasts decades, and is a suitable tracer of recently emitted carbon dioxide from fossil fuel combustion,” explained Maximilian Reuter, lead author of the study.

“Sciamachy measured nitrogen dioxide and carbon dioxide simultaneously. We used a spatial high-pass filtering method to isolate the anthropogenic carbon dioxide signal from overlaying signals due to uptake and release of carbon dioxide by vegetation.”

Satellite-derived CO2 concentrations proportional to local anthropogenic emissions in North America and Europe. 

The green line shows the mean value and the grey-shaded area its variability and uncertainty. 

This indicates that less CO2 is emitted during weekends compared to week days.

Using this method, the scientists were able to better see where and when carbon dioxide was emitted.

For example, it showed that less carbon dioxide from local anthropogenic sources is emitted during weekends in Europe and North America compared to week days.

“This has never been observed from space before and shows how accurate the used method is,” said Dr Reuter.

Although Envisat’s mission ended in 2012, a decade of data from its 10 instruments is still being exploited for studies on Earth’s atmosphere, land, oceans and ice caps.

“Unfortunately, none of the existing nor any of the planned near-future satellites are designed to directly observe carbon dioxide emissions of cities, power plants, volcanoes or other important emission hot spots,” said Michael Buchwitz, co-author of the study and GHG-CCI scientific leader.

“This will only be possible with the proposed mission CarbonSat.”

CarbonSat is one of the two candidates for ESA’s eighth Earth Explorer satellite.

Using the unique spectroscopic fingerprint of carbon dioxide and methane, CarbonSat aims to image these two strong greenhouse gases at very high resolution.

The mission would lead to a better understanding of the sources and sinks of atmospheric carbon dioxide and methane.

Scottish Mullite: Silicate Material That Can Cut Diesel Pollution

Platinum, a rare and expensive metal, is currently used in diesel engines to try to control the amount of pollution released into the air.

Scientists have now developed a new material that is much more effective than platinum in reducing pollution. University of Texas at Dallas scientists have found that oxide mullite could reduce pollution up to 45 percent compared to platinum crystals.

Mullite or porcelainite is a rare silicate mineral of post-clay genesis, They claim that mullite is less expensive to produce compared to platinum crystals.

Mullite was first described in 1924 for an occurrence on the Isle of Mull, Scotland. It occurs as argillaceous inclusions in volcanic rocks in the Isle of Mull and also with emerylike rocks in Sithean Sluaigh, Scotland.

"Many pollution control and renewable-energy applications require precious metals that are limited - there isn't enough platinum to supply the millions and millions of automobiles driven in the world," said Dr Kyeongjae "K J" Cho, professor at the University of Texas.

"Mullite is not only easier to produce than platinum, but also better at reducing pollution in diesel engines."

Diesel engines give higher fuel efficiency compared to gasoline but produce more nitric oxide (NO) and nitrogen dioxide (NO2), which are quite harmful to human health.

Recently, the World Health Organisation (WHO) upgraded the classification of diesel engine exhaust as carcinogenic in humans, putting it in the same category as cigarette smoke and asbestos.

Countries throughout the world have drafted guidelines to reduce diesel air pollution in the next decade.

The new material developed by scientists could be a new cheap and effective way to reduce pollution.

The discovery was made while analysing the chemical components of mullite.

The team used advanced computer modelling techniques to analyse how different forms of the mineral interacted with Oxygen (O) and Nitrous Oxide (NOx).

The study revealed that the oxide mullite reduces pollution up to 45 percent compared to platinum crystals.

"Our goal to move completely away from precious metals and replace them with oxides that can be seen commonly in the environment has been achieved," Dr Cho said.

"We've found new possibilities to create renewable, clean energy technology by designing new functional materials without being limited by the supply of precious metals."