Evidence for climate change

Like clockwork, birds start singing outside my window at 00:30, every night! Each time I hear them I become instantly annoyed - birds singing at night is not calming for me. Instead, I sit there and wonder (after cursing a lot) the same things; Why are you up at this hour, it's night time?! Why have you not migrated to a warmer climate?

I then got to thinking, and with all the news lately about 2015 being the hottest year on record, I realised... They're staying here because it's (clearly) not that cold! The fact of the matter is, this is evidence that the world is warming. Winters here are much milder than they once where. The last time the world had a record cold year was back in 1909, over 100 years ago!

Since the millennium, 14 of the 16 'hottest on record' years have occurred, and it seems like each year is another new record. Warmer years have been recorded since the 1930's, with a few blips here and there, but the overall analysis of the past 150 years or so, shows a rise in temperature. It's not a coincidence that the warming started then- around the start of the 19th century is when the industrial revolution came to play. You know what that means! ... Carbon burning - a rise in CO₂ emissions and greenhouse gases. Scientists have been able to analyse bubbles trapped in ice from the Antarctic for the past 800,000 years; the results support the notion that the rise in CO₂ is human related. Natural cycles related to things such as volcanoes and ice ages allowed the CO₂ concentration in the atmosphere to fluctuate, anywhere between 170 parts per million (ppm) to 300ppm. However, since around 1850, the concentration has only been rising, with it's current level at 402ppm! The past 800,000 years has never had an increase above 300ppm!

Global annual average temperature measured over land and oceans. Red bars indicate temperatures above and blue bars indicate temperatures below the 1901-2000 average temperature. The black line shows atmospheric carbon dioxide concentration in parts per million.

It's clear that the rise of the industrial revolution brought a change not just to temperature but the amount of carbon dioxide we have in our atmosphere. It's no news to you that carbon dioxide is a greenhouse gas, and what do greenhouse gases do? They alter the natural process of the greenhouse effect - the Earths' atmosphere traps in some of the heat radiated from the Sun, allowing most of the rays to bounce off the Earth as infrared radiation. The build up of greenhouse gases acts like a cloud, which traps these 'bounced off' rays, making the atmosphere warmer.

There's ample evidence and data that supports the notion that greenhouse gases are contributing to the rise in global temperatures. But for those of you that aren't satisfied with that, and say 'but the Earth changes temperature all the time, look at the ice ages', I say, here's what other evidence there is that climate change IS happening:

-Global sea levels are rising. In the past 20 years, the average rate of increase is around 3.5mm/year. Before that, it was approximately 1.7mm/year since 1880. They can rise for two reasons, either the water is warming and therefore expanding, or, ice is melting ... which brings me onto ...
-The volume of glaciers around the world is declining. There's a lot of evidence of global glacial retreat. I can bet you that if you went to see one 10-20 years ago, it would look different now, larger perhaps.

A lot of imagery and info for you there, but this is just a snippet. Evidence for climate change is not hard to find, temperatures are changing and accelerating at worryingly rapid rates. Even if you still believe that warming isn't induced by humans, you cannot escape the evidence that warming is happening, and that's the problem. Things will start to get worse if it keeps warming (one of my previous blogs touches on what will likely happen). Before I know it, I'll have a tropical rain-forest outside my window and I'll never sleep!

Say no to drugs!

In my previous blog I touched upon the presence of Ethinyl Estradiol 2, a synthetic hormone commonly used in the contraceptive pill, being present in marine systems, and how they can alter the endocrine system of aquatic life. It may or may not come as a surprise to you that traces of illicit drugs, such as cocaine and MDMA (ecstasy) have also been found in waste water systems, as well as pharmaceutical drugs like ibuprofen and various antibiotics.

A study, reviewed the effects these drugs have on aquatic organisms, and the results weren't great. Many of the chemicals released from these drugs, in particular, from cannabis and cocaine, showed DNA damage, even at low levels of concentration - 40ng/L concentration was shown to effect D. polymorpha (a type of mussel) in this way. They also looked into illicit drugs found in river sites, and found concentrations up to 25ng/L of MDMA and 17ng/L of cocaine. Alarmingly high in comparison to the results found in the River Thames back in 2008, where cocaine ~4ng/L and MDMA ~4ng/L.
The results are in nano-grams per litre. Though this is a small measuring, if you take into account that the river has many currents and tidal flows from the rivers' source, which dilute the water, the amounts are likely to be concentrated higher in urban areas.

Many traces of antibiotics were also found in this study which can also be toxic to acquatic organisms. But it's not just animals that are at risk, humans are too. We're at a time where it is of growing concern how many antibiotics we're using in the world, with the risk of antibiotic resistance ever increasing. These illicit drugs and chemicals have the potential of ending up in our drinking water. Overtime, daily consumption of nano amounts can have a great impact.

So think twice before taking any drug! And maybe buy a water filter system for your home tap, just to be safe!

Ladies, stop taking the pill!

Ethinyl Estradiol 2 (EE2) is a synthetic hormone, that is a bioactive oestrogen, used commonly in medication (the contraceptive pill for example), as well as livestock (to improve the productivity). EE2 is also used in aquaculture, to farm single-sex populations of fish.

A conceptual diagram of how EE2 enters the acquatic system through various sources

It is of growing concern to the environment because of its ability to be absorbed into organic matter, concentrate in biota, and accumulate in sediments. They enter the environment generally through wastewater systems, and by manure.
I mentioned how EE2 can be used in aquatic systems, to control the growth and population of farmed species. The problem with this, is there's a lot of 'waste' that spills into surrounding areas of water. Approximately 70% of the chemical 'spills' out due to over feeding of fish; this also triggers areas around the world where EE2 is more commonly found in the water. This translates to local freshwater being contaminated, a problem because humans drink this water- it has been found but not confirmed that the chemical can cause a decrease in fertility, and may cause cancer.

Many past studies concluded that these EE2 hormones can be highly toxic to exposed aquatic species. These are some of the effects:
-An increase of plasma vitellogenin (a gene) in male and female fish
-An increase of intersex fish
-A decrease in egg and sperm production
-A reduction in gamete quality
-Male fish changing sex
-Reduced fertility
It also has the ability to change the behaviour of a species. Reyhanian et al. (2011) proved that EE2 affected the shoaling behavior in adult male zebra fish. Those that were exposed to higher concentrations had a greater reduction in swimming activity, and spent a lot of time near the surface, compared to fish exposed to much smaller doses.
Amphibians and mammals have also been proven to be affected by EE2. The Northern leopard frog was seen to have altered sex ratios of tadpoles, with a dominance of females. The metamorphism process was also delayed by up to two weeks. Controlled experiments on mice led to the conclusion of a retardation in their growth.

EE2 has the ability to be absorbed into organic matter, so there are often higher concentrations of the hormone found at the bottom of water systems, in the sediments. They can actually encourage the EE2 to settle due to the hydrophobic properties of the sediments, with concentrations being 1000 times higher than levels recorded at the surface of the water. This is problematic, because it also means that the hormone can stay in the environment for a longer period of time, especially if sediments deposit on top, creating beds. Benthic invertebrates are left extremely vulnerable because of this. Labadie and Hill (2007)

So we know that EE2 can be some what problematic to the environment, but it's not that easy to get rid of it. We cannot just ban them, because they have become an important factor in everyday lives. Studies have found that EE2 can be removed from the environment completely, by the use of microbes and bacteria, by the process of biological degradation.  But it's not easy to introduce a bunch of bacteria into water systems without complications- this would be expensive, and we do not know what the long term effects are. Filter systems can be put in place in sewage systems, but this too is costly, not to mention the amount of energy that would be used to do so. I think it's important to study the sediments of water basins; if they hold much higher concentrations of EE2, finding a way to clean them may help reduce the amount of EE2 dramatically.

Cigarettes... An overlooked entity?

I recently saw a powerful advert by the Food and Drug Administration, encouraging people to stop smoking. It got me thinking about how harmful they are, not just to humans... to the environment.

It comes as no surprise that it can impact the environment in some way. We are blowing out thousands of chemicals, from arsenic and ammonia to hydrogen cyanide, which aren't exactly a good thing. All of these chemicals have the potential to be absorbed by the globes' water, damaging fish and micro-organisms.

But it's not just the toxic chemicals that are harming the environment - production and waste is a major problem.

600 million trees are cut down every year to make the papers for the 6 trillion cigarettes that are produced globally each year. A length of 4 miles of paper is used to produce cigarettes each hour! And machines are used to make them, powered by coal no doubt.

Countries where tobacco is grown, like Uganda, have experienced massive areas of deforestation. According to an article by IRIN Africa, the country has lost almost a third of its trees in the past 20 years, and unless we stop exploiting these forests, by 2050 there won't be any left! This will have a huge detrimental impact on the country in many aspects; agriculture will decline, the majority of the population will suffer, farmers won't be able to harvest, water resources will be scarce, diseases will spread, and animals will disappear, with some species becoming extinct.

Then there's the cigarettes themselves. Globally, two thirds (about 4.6 trillion) of all cigarettes smoked are being tossed into the environment. Butts and filters are the most common waste product being found and cleaned up on beaches world wide. A handful of studies have suggested that chemicals absorbed into the butts and filters, such as pesticides and arsenic are seeping into water, affecting aquatic life. Butts that are discarded on the roadside also contaminate the environment by releasing chemicals, and heavy metals such as lead and copper. 

The majority of filters are made of paper and rayon wrapping, which controls the airflow. Glue is also used to hold the cigarette and filter together, and a variety of alkali metal salts are found in cigarettes to help keep them burning. Plastic is also used in many of the filters, which is non-biodegradable - a problem which you should now be familiar with if you've been keeping up to date with my blogs!

All of these elements pose a massive threat, because they can remain in the environment forever. (Novotny et al 2014)

It's not just small organisms and marine life that are effected, humans are too. These chemicals can contaminate the food we eat, and the water we drink. Below is a great diagram I found that shows some of the ways in which humans are at risk:

People need to be made more aware about the impacts of cigarettes on the environment, not just to our own health. As an ex-smoker, I definitely didn't think twice about these threats, or what damage flicking a butt out of my car window can actually do. At least with some awareness, maybe it can encourage people to discard butts and packets properly (in the designated bins).