Scientists from around the world have become embroiled in a war of words over energy created from burning trees. A recent report claimed that burning wood for electricity if worse for the climate than using coal, prompting major questions and enquiries over how we should generate electricity whilst preserving our environment.
Producing electricity from burning biomass such as trees has boomed in recent years, with the amount of energy generated doubling between 2005 and 2015. Many energy firms around the world have seen it as a more reliable green power source compared to using wind or solar power. The EU, the world’s biggest consumer of biomass, with some imported as wood pellets from Southern USA. At the current rate, bio-energy is expected to contribute more than half of the EU’s renewable energy by 2020.
Burning down trees also costs a lot of money, with subsidies worth £800m paid by the UK government for biomass electricity in 2015.
The study also showed that the amount of time it would take to re-absorb the carbon produced from burning of pellets was critically important. With scientific concern over the world, the world only has a few more years to make significant cuts in carbon dioxide levels, opting for a policy that would also take many decades to achieve carbon payback was dubious.
The idea that burning wood released more carbon dioxide than coal has enraged those who work in the biomass industry and people who carry out research. Many of them described it as “it gives an inaccurate interpretation of the impact of harvesting on the forest carbon stock”. The author argued that there is no accounting for the sole carbon lost during the harvesting of these trees and that older trees used for burning can sequester far more carbon than younger ones planted in their stead.
Whatever may happen in the coming decades, the fact that we need trees to survive does not go away from us, therefore a global limit should be put in place stating the number of trees than can be used to generate energy. With growing levels of deforestation globally, there is more CO2 in the atmosphere, which if increased could cause serious health problems and create an unpleasant environment for us to live in…
Air pollution is a major contributor to ill health in the UK. Dirty air does not directly kill people; it cannot. However, it is estimated in the UK to contribute to the shortening of the lives of around 40,000 people a year, undermining the health of people with heart/lung problems.
In cities worldwide, pollution is increasing. Although, in the UK, air pollution levels have been generally decreasing. In many big UK cities safe limits on harmful particulates and oxides of nitrogen - NOx - are still regularly breached.
Experts in air pollution have argued that it has been under reported for decades and the issue has been thrust into the news because the UK government lost court cases over illegally dirty air and car makers were found to be cheating tests on car emissions. Scientists are also more confident now about the ways that air pollution harms people. It has recently been linked with dementia although that link remains debatable.
Diesel car manufacturers drew fire by cheating emissions tests. Diesel is much more polluting than petrol on a local scale, and the biggest proportion of pollution in the UK cities comes from road transport. However, in Greater London, private diesel cars contribute 11% of NOx - less than what people might have thought. Lorries - with far fewer on the roads produce the same amount. In Central London, just 5% of NOx comes from private diesel cars, compared to the 38% from gas for heating homes and offices.
Solving air pollution needs a many sided approach. The best value for money comes from targeting the really big individual polluters such as old buses and lorries. Insulating homes so they don’t burn as much gas would also save pollution. Furthermore, stopping the spread of wood burning stoves in cities might help and cutting pollution from ships would be a good port in cities. Reducing use of chemicals in the home would help a little bit. Ministers are also under pressure to offer a £3500 incentive for drivers to scrap old diesel cars, and politicians are nervous upsetting drivers.
In recent times, rapid rises in global temperatures have led to a boost in mercury levels in fish by up to seven times the current rate, increasing by 200% and 500% researchers have concluded.
Experiments have been carried out by researchers and scientists, in which they have found that the extra rainfall drives up the amount of organic material flowing into our seas. With this extra organic material, food chains are altered and the concentration of mercury increases. Along with this, mercury is bioaccumulating, and is built up in the adipose tissue of successive trophic levels; leading up to larger fish, and this causes an overall increase in the amount of mercury in fishes, furthermore leading to many issues. Mercury has a significant impact on the central nervous system, and produce harmful effects on the digestive and immune systems, too much mercury can lead to fatal consequences, and we need to solve this issue.
Mercury is one of the world’s most toxic metals. It is also one of the top ten threats to public health, according to the World Health Organization. The effects high levels of mercury can have are substantial, with damage to the nervous system, paralysis and mental impairment in children just some of them. One of the most common form of exposure to mercury is by eating fish which contain methylmercury. This is an organic form of the metal which forms bacteria, when reacted with mercury found in water, soil or plants, at the expense of phytoplankton.
Under the warmest climate scenario, there would be an increase in organic matter runoff of 15-20% by the end of the century. This would see levels of methylmercury in zooplankton, which is the bottom link in the food chain, grow by two to seven fold. There would be different impacts suffered around different parts of the world, with lakes and coastal waters in the northern hemisphere being most likely to have a significant increase in methylmercury fish. The mediterranean and Southern Africa will likely see reductions.
Researchers hope that the Minamata treaty will be successful and countries reduce the amount of mercury being produced. With many countries relying heavily on fish as a source of food, and the level of fish being eaten all over the world, the level of methylmercury within human bodies is likely to increase. If the level is not decreased, the impacts to human health could be severe. To add to our woes, the appointment of Donald Trump’s cabinet, contains many climate change sceptic members, and this could lead to an increase in the mercury problem we are facing.