Everyday we are constantly bombarded by the negative effects of global warming. However, scientists from the UK’s National Centre for Atmospheric Science and Universities of York and Leeds, has some very positive news to share. Vast amounts of ozone – 50% more than what is predicted by the world’s-state-of-the-art climate models – are being destroyed in the lower atmosphere over the Tropical Atlantic.

This news is specifically important because the ozone in the lower atmosphere acts as a greenhouse gas. Its destruction also leads to the removal of the third most abundant greenhouse gas: methane.

Research Findings on Greenhouse Gas Loss

The findings came from analysing data from Cape Verde Atmospheric Observatory – recently set up by British, German and Cape Verdean Scientists. The scientists analyzed the first year of measurements from the observatory, and alerted by these data, flew a research aircraft into the atmosphere to measure ozone at different height and widely across the Tropical Atlantic. The results are similar to those made at the Observatory. It also showed vast ozone loss throughout the remote area.

Causes of Greenhouse Gas Loss

Instruments developed by people a the University of Leeds in the UK, which is also used at the Observatory, found that there is bromine and iodine oxide present over the area. These chemicals are produced by sea spray and are emitted by phytoplankton, causing the ozone to break down. The destruction of the ozone produces a chemical which destroys the methane.

Measurement and Experiment are irreplaceable

Monitoring the atmosphere over the Tropical Atlantic had not been possible before because of its physical inaccessibility. But now, with this new chemistry included in climate models, it can provide us with more accurate measurements of ozone and methane in the atmosphere. Thus, we will can make better climate predictions for the future.

Experts Take on This Startling Discovery

Professor Alastair Lewis, Director of Atmospheric Composition at the National Centre for Atmospheric Science and a lead scientist in this study, said: “At the moment this is a good news story — more ozone and methane being destroyed than we previously thought - but the tropical Atlantic cannot be taken for granted as a permanent ’sink’ for ozone. The composition of the atmosphere is in fine balance here- it will only take a small increase in nitrogen oxides from fossil fuel combustion, carried here from Europe, West Africa or North America on the trade winds, to tip the balance from a sink to a source of ozone”

Professor John Plane, University of Leeds said: “This study provides a sharp reminder that to understand how the atmosphere really works, measurement and experiment are irreplaceable. The production of iodine and bromine mid-ocean implies that destruction of ozone over the oceans could be global”.

Dr Lucy Carpenter, University of York and UK co-ordinator of the Observatory added: “This observatory is a terrific facility that will enable us to keep an eye on the chemical balance of the atmosphere and feed this information into global climate models to greatly improve predictions for this region in the future”.

Posted in Global Warming

Though the flooding in central England nearly a year ago were very severe, a scientific analysis on the event say that they cannot be linked to climate change.The magnitude of last July’s flooding prompted experts to say that they were due to climate change and an indication of similar summer-time flooding to come.

But, as per the report published by the Centre for Ecology and Hydrology in Wallingford, experts say that there is a trend for less flooding during summers and more rainfall during winters. Researchers of said institute analyzed flooding trends for the last fourty years all across England, and arrived at this conlusion.

Terry Marsh of the Centre for Ecology and Hydrology said “the raindfall…was remarkable” and it fired speculations that the increasingly risky floods are due to global warming. “Due to the inherent variability of the UK climate, any extreme hydrological event cannot readily be linked directly to climate change” said Marsh.

The researchers also added that a historical view showed how truly phenomenal last year’s floods were. The affected areas include Gloucestershire, Oxfordshire, and towns along the rivers Severn and Avon.

Reviewing data that went back to 1766, from May to July last year, the average rainfall for England and Wales was 415 mm. This is the highest ever recorded. In a table showing the 15 wettes years only one other year occurred in the 20th century - 1924. In summer of that year (May to July), 308 mm of rainfall fell. That is 107 mm less than last year’s and is said to be the equivalent of seven weeks of average rainfall.

The detailed data on the river flows for the last 40 years only supports the theory that last years flooding was exceptional. Marsh and Jamie Hannaford show, in an analysis in the International Journal of Climatology, that river flows did increas but the said increases are mostly confined to the north and west. Hannaford said that “This trend is driven by an increase in, generally, winter high flows”. Thus, last year’s summer floods happened in the wrong season and the wrong place which means that “The summer 2007 floods don’t really fit into these patterns.”

The increase in winter flooding would fit prediction of some climate modellers for wetter winters and dryer summers. But, Hannaford said that it cannot be accurately determined whether the trends in the data are due to global warming. The British climate is too inconsistent from year to year to know for certain. Hannford adds “We have only 40 years of data which generally is too short to determine whether or not these trends are caused by any underlying climatic mechanism.” And even if the rainfall increases due to climate change, it might actually lowers the flood risks at some times of a year because there would be less snow melt in spring and the higher temperatures dry soild earlier.

Marsh said that climate change could even provide a “silver lining” due to the fact that drier summers could limit the winter flood period because the soil would absorb more water.

Posted in Floods