A crystallised skeleton of a minke whale features in an exhibition on climate change as a symbol of the warming of its natural environment, says Chris Holt
"Stranded" is made from a six-metre minke whale skeleton encrusted with transparent crystals of alum, and displayed on a low illuminated plinth.
The crystals brilliantly reflect light, seeming to entomb the skeleton.
Transience, a feeling of pain, danger and fragility seem to pierce the viewer as the skeleton seems almost to pierce the alum crystals.
This work was created when the artists removed the remains of a whale that was washed up on a Skegness beach. They cleaned the bones and immersed them in an alum solution to generate crystal formation.
Heather Ackroyd and Dan Harvey recently visited the Arctic; they created this artwork from their experiences in that extraordinary place. They are making a statement about climate change, something that is of increasing concern to all of us. For the past 14,000 years, the temperature of the Earth has been very stable, with variations of no more than 1 degree centigrade. During this period, mankind has developed most of what we would regard as civilisation: agriculture, science, technology, medicine, literature, art, and the establishment of political and judicial systems.
However, this long period of temperature stability is now coming to an end.
Human activity has now reached the point where it is contributing to a warming of the planet, which is already showing itself in some alarming ways. There has been a widespread retreat of mountain glaciers across the globe, and in recent years northern hemisphere sea-ice has decreased by about 15 per cent. The polar icecaps are melting, releasing fresh water into the oceans, raising sea levels and slowing the circulation of ocean currents. Globally, weather is now more unstable, with increasing floods, droughts, heat waves and windstorms.
The Arctic is a good place to see what is taking place. Sir Peter Blake wrote recently in The Independent: "I am speaking from an area of water that has never been water before. It has always been frozen solid. It is uncharted. There are no depth readings on the map because no ship has ever been able to measure them. No one has ever been anywhere near where we are now. We have sailed for the last 100 miles through open seas in an area that in the past would have only been accessible to the biggest ice-breakers. Now it is clear water."
How does global warming work? For the planet to remain at a constant temperature, the amount of heat radiation arriving at the Earth from the Sun must be equal to the amount of heat radiated from the Earth back into space. This is what has been happening for the past 14,000 years: the two have remained in balance.
The Sun's rays do not heat the Earth's atmosphere directly as they pass through it on the way to the surface. However, the heat radiated back into space from the Earth does heat the atmosphere, because it has a long wavelength which is absorbed by the greenhouse gases in the atmosphere. We do need some greenhouse gases to keep the surface of the planet warm. The planet Mars has no greenhouse gases and is extremely cold. Venus has a high concentration of these gases in its atmosphere and is very hot, too hot to support life.
Human activity has resulted in large quantities of greenhouse gases - particularly carbon dioxide - being released into the atmosphere, thereby increasing its potential to absorb the heat which otherwise would be radiated back into space. We still have the same amount of heat arriving from the sun, but less of that heat now being radiated back out into space.
So we warm up - we are living in a greenhouse.
Now artists are getting involved in drawing the attention of the public to climate change. Artist and filmmaker David Buckland founded Cape Farewell, a group of arts people who explore the seas to understand the changes taking place in our weather and climate. Cape Farewell, or Kap Farvel, is on the southern-most point of Greenland.
Artists such as Rachel Whiteread, Antony Gormley and Kathy Barber have travelled to the Arctic to get inspiration for new artworks to represent the implications of climate change. The Natural History Museum is staging an exhibition displaying some of this work, entitled The Ship: the Art of Climate Change. The ship in question is the Nooderlicht, the 45-metre schooner which took the artists to the Arctic.
Other works in the exhibition include a film projection called "Endangered Species" by Siobhahn Davies, showing a dancer, Sarah Warsop, whose graceful movements become increasingly obstructed by white rods which multiply in number as the dance progresses, so that they eventually restrict and extinguish her. Gary Hume has made a poignant painting of a hermaphrodite polar bear representing the distressing effects of chemical pollution on wildlife. Max Eastley's recordings of cracking ice resonate eerily.
Bergit Arends, of the Natural History Museum, said: "Articles on climate change appear almost daily in newspapers and on television and it can appear that such issues are beyond our control. This is why we are trying to use the personal experiences of renowned artists and the creative vocabulary of art rather than science to raise an awareness that everyone individually can help alleviate the impacts of climate change."
= www.bbc.co.ukclimate www.ch4.org.uklessonplans.php
Chris Holt is a freelance science writer
(both born 1959)
Heather Ackroyd has worked in sculpture, in particular with processes of growth and transformation. Dan Harvey often uses found objects in his sculptures where the effects of nature can be seen. These two artists collaborate on installations and sculptures and are most famous for using grass - pictures grown on grass canvasses, grass growing on walls and grass coats displayed at fashion shows. Harvey says: "In the greater body of our artwork we play with many materials exploring processes of growth, transformation and decay, and we embrace the transience and ephemeral nature of our materials."
* The minke whale is the smallest of the baleen (filter-feeding) whales.
Males can grow up to about 10 metres and females to 11m. They feed on plankton, krill and small fish. They are found worldwide but are less common in the tropics. They usually travel singly or in pods of two or three.
* The Ship: the Art of Climate Change is at the Natural History Museum until September 3. Admission free
Ask pupils to make a list of all the appliances in their homes that use energy. Ask for suggestions as to which use the most energy.
Ask pupils to estimate how much each household appliance uses per hour and per year. List ways that energy could be conserved in the home.
Car-makers now publish figures showing how much carbon dioxide their cars produce. Ask pupils to calculate how much carbon dioxide they generated on their journey to school.
Add them all up and see how much carbon dioxide was released in getting the whole class to school. How could this be reduced?
Discuss how the AckroydHarvey minke whale sculpture communicates the dangers of climate change. Make your own picture, sculpture or installation representing climate change. You might think about materials which decay or are degraded by the influence of some agent. Photos or paintings could be organised into a montage. Perhaps greed and excessive consumption could be expressed using waste packaging or discarded mobile phones.