A vast glasshouse complex in Thanet is one of the greatest sources of light pollution in the country. Steve Geliot has been researching the potential impact on both people and wildlife and suggests that it really should not be too difficult to design structures that are kinder to us all.
In 2001 a movie called The Glass House tanked at the box office and lost a lot of money. Released just days after the 9/11 attacks, you could put this down to being the wrong film at the wrong time, but critics were generally in agreement about its shortcomings. The website Rotten Tomatoes says: “Due to obvious plot twists and foreshadowing, The Glass House fails to thrill. By the end it degenerates into ludicrousness”.
Birchington has what many might call a ludicrous glasshouse story of the literal variety – one that, in terms of environmental credentials, might merit a rotten tomato or two.
In my work as a campaigning artist, I have found myself becoming a citizen scientist using remote sensing from satellites to map and measure light pollution, thanks to some amazing mentoring from Professor Chris Kyba in Potsdam.
The group of glasshouses near Birchington known as Thanet Earth stands out as one of the worst sources of light pollution in the entire country.
Its green-and-blue-branded website states that the site grows tomatoes, cucumbers and peppers – vegetables that one might normally import from the sunnier parts of southern Europe. This could potentially be a good thing since it avoids emissions created by long-distance hauling of produce.
The website boasts that “Britain’s leading glasshouse complex sits proudly within the landscape of East Kent” and adds that “innovation, environmental concern and a focus on quality combine with cutting-edge technology, international expertise and the best growing conditions in the UK to produce unrivalled taste on a commercial scale”.
If we are avoiding all the carbon emissions of shipping produce from Spain, surely these are fair claims?
Well, maybe not. I’m not an expert on hydroponics, so I don’t know what sort of chemical fertilisers or pest and disease controls are used, or if any of these things find their way into the environment. However, as well as having a rough idea of electricity consumption, we can measure the light emissions without putting a foot inside the building.
The units (summed radiance nW/cm2sr) can seem confusing, so let’s make a quick comparison. An area of about 4 sq km in the West End of London, including Leicester Square, emits about 3,600 units and is actually decreasing in brightness by 0.5 per cent a year, owing to small improvements in street-light design. By comparison, the same area at Thanet Earth is emitting about 12,000 units, and this is increasing annually by an average of 12.5 per cent a year. That is three times as bright as central London.
The website accepts Thanet Earth uses some 40,000 lights, each of which is 1,000 watts. Just think about it for a moment: that equates to some 40 million watts of electricity being used.
The Eye Hortilux High Pressure Sodium bulbs used are not efficient and pump out a huge amount of heat. I know because I bought one to test.
The lights at Thanet Earth come on at night but can stay on during the day to supplement daylight – so maybe they are burning for about 17 hours a day during winter.
The website talks about blinds to screen off the light and that unavoidably there are some small gaps; however, when I visited at night and photographed this impressive volcano of light pollution I could see no evidence of such blinds. There was some ragged black plastic mesh on the sides of the glasshouses, but a vast amount of light and heat was bouncing straight up into the sky without any effective measure to contain it.
If we are going to take any environmental claims seriously, we need to see some comparative figures for the emissions involved in transporting tomatoes from Spain against the emissions, including light emissions, from these glasshouses. Only then can we assess what is going on from a net-zero perspective.
Why does it matter? Well, the climate-busting use of electricity is obvious, but science is showing that artificial light at night is driving insect declines, impacting on bird migrations, and evidence is growing about the ways in which light pollution impacts human health.
Artificial light increases obesity rates and drives anxiety and depression, especially in teenagers. That is why the screen colour of iPhones changes in the evening. These well-researched harms to your health are known and manufacturers don’t want to be sued.
Chronic exposure to artificial light at night also makes it a little more likely that pre-cancerous cells in breast tissue change and become active cancer. If you already have breast cancer and are on a drug called Tamoxifen, then that drip-drip chronic exposure to artificial light at night makes the Tamoxifen less effective and reduces the chances of recovery.
Artificial light at night and poor sleep are also implicated more generally in inflammatory illnesses, while there is growing evidence about its role in thyroid cancer.
We can take a more detailed look at how light pollution affects birds. I have been filming the iconic starling murmuration here in Brighton for the last eight years and as part of that have been learning about the science of how and why these dazzling birds do it.
I have also investigated the causes of the dramatic declines that have brought our Brighton murmuration from 100,000 birds in the 1960s to 10,000 last year and just 6,500 this year. The main cause is thought to be insect declines, meaning the starlings don’t have as much to eat.
These insect declines are caused primarily by pesticides, but light pollution also plays a significant role in driving insect decline. Maybe there is even more to consider. Our dwindling UK starling flocks consist of birds that live here year-round that are joined in autumn by many hundreds of thousands that migrate to the UK from areas of north-east Europe with cold winters.
These migrations across the North Sea between The Netherlands and Norfolk take place at night. The Dutch and Belgian coasts are the brightest part of Europe due to the hundreds of greenhouses just like Thanet Earth. This light pollution, mainly from the area known as Westland, close to Rotterdam, is six times as bright as that in New York.
To navigate at night, starlings, as well as many other birds, use a sense called magneto-reception, meaning they can literally see Earth’s magnetic field. However, it is quite a subtle sense and seriously disrupted by light in the yellow to red part of the spectrum, which is exactly what is emitted by these huge greenhouses.
Starling mortality appears to be occurring mainly in juveniles failing to make it past their first year. Juveniles have not yet established or learned their migration route, so their first journey is an epic challenge. Their magneto-reception is only just forming and is probably weaker and more vulnerable to this kind of sensory pollution. My theory, and it is only a theory that has yet to be researched, is that some losses might be explained by juvenile birds not successfully navigating their first migration past that huge wall of light on the Dutch coast.
Brightly-lit glasshouses in the UK will probably also be problematic for bird navigation.
If you mess with the natural day-night arrangement to the extent that is happening at Thanet Earth, and on an even larger scale in Westland, you are not really a friend to wildlife and it is questionable whether you are a friend to the wider community.
If we take a forensic look at the cost of these huge, arguably badly-designed glasshouses in terms of climate, in terms of wildlife and in terms of human health, we can only conclude that, in this instance at least, modern farming degenerates into ludicrousness.
Environmentally speaking, I believe these really are rotten tomatoes. It is frustrating because it is simply a matter of design. We have world-class glass manufacturers in the UK, so surely it would be possible to develop a world-class design for a glasshouse that allows light in but doesn’t allow light out.
Tuesday, May 10, 2022