He argues that storing up expensive and destructive consequences for society in future is an “injustice of one generation to others”.
Hansen will argue in his lecture that current generations have an over-riding moral duty to their children and grandchildren to take immediate action. Describing this as an issue of inter-generational justice on a par with ending slavery, Hansen said: “Our parents didn’t know that they were causing a problem for future generations but we can only pretend we don’t know because the science is now crystal clear.
"We understand the carbon cycle: the CO2 we put in the air will stay in surface reservoirs and won’t go back into the solid earth for millennia. What the Earth’s history tells us is that there’s a limit on how much we can put in the air without guaranteeing disastrous consequences for future generations. We cannot pretend that we did not know."
When the space ship Endeavour launched last week, it was carrying an unusual cargo: a baby bob-tail squid.
This is not because the astronauts want a change in their menu: the squid could help us understand how “good” bacteria behave in the microgravity of space. As Jamie Foster of the University of Florida in Gainesville, who is running the experiment, puts it: “Do good bacteria go bad?”
We already know that disease microbes grow faster and become more virulent if they are sent into space. In 2006 Salmonella bacteria were sent up on a space shuttle, and when they returned to Earth they were almost three times as likely to kill mice as normal (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0707155104). Escherichia coli also changes its behaviour. These studies all focused on harmful bacteria. “This is the first to look at beneficial bacteria,” Foster says.
Foster has arranged to send up the bobtail squid Euprymna scolopes, a Pacific species that carries a cargo of bacteria called Vibrio fischeri in its body. The microbes colonise young squid soon after the squid hatch and set up home in their light organs. The squid use the bacteria to generate light, which they shine downwards to ensure they don’t cast a visible shadow.
Foster’s experiment is simple. Newly hatched squid that have not yet encountered their bacterial partners will go up to orbit in tubes of seawater. Fourteen hours after launch, an astronaut will add the bacteria and give them 28 hours to colonise the squid. Then the squid will be killed and fixed solid, and brought back to Earth for examination.
Foster has some preliminary results from Earth-bound experiments that simulated microgravity and appeared to show problems with the uptake of bacteria by squid. If the shuttle study shows the same result, it would suggest that astronauts’ relationships with their own microbes might also be affected in space. “We want to make sure the astronauts are healthy,” she says.
Foster developed the experiment with Margaret McFall-Ngai of the University of Wisconsin-Madison, the Florida Space Grant Consortium and students from Milton Academy in Massachusetts and Merritt Island High School, Florida.