Contemporary environmental activist and writer David Orr, in Ecological Literacy: Education and the Transition to a Postmodern World says:

The crisis of sustainability, the fit between humanity and its habitat, is manifest in varying ways and degrees everywhere on earth. It is not only a permanent feature of the public agenda; for all practical purposes it is the agenda. No other issue of politics, economics, and public policy will remain unaffected by the crisis of resources, population, climate change, species extinction, acid rain, deforestation, ozone depletion, and soil loss. Sustainability is about the terms and conditions of human survival, and yet we still educate at all levels as if no such crisis exists.

We humans have not made a very good job of caring for planet earth, particularly over the past century. The following selected details, taken from a variety of sources, seem to me to be particularly significant. Scores more worldwide could be cited but these will highlight the problem.

Climate change

NASA scientist, James Hansen, says that 350 parts per million of CO20is the limit if we want to avoid major catastrophe. At the time of writing it is in the 370s and rising.

A report from the World Humanitarian Forum, led by Kofi Annan, the former UN Secretary General, suggests that global warming is already killing an estimated 300,000 people a year. 90% of those deaths are related to environmental degradation resulting from climate change—principally malnutrition, diarrhoea and malaria. The remaining 10% are linked to weather-related disasters. This figure is projected to rise to 500,000 by 2030.

According to the United Nations, climate change will result in at least an additional 150 million environmental refugees by 2050.

Michael S. Northcote, in A Moral Climate, says that in the last three hundred years 600,000 million tonnes of the carbon formerly locked in the earth, has been dug up and added to the carbon cycle.

According to the CDIAC data center, in the past 400,000 years the planet has never had so much carbon dioxide in its atmosphere as it does today, and the levels are continuing to rise.

1998 set a record for economic losses from weather related disasters up to that time, with an estimated $90 billion worth of damage, not to mention that 32,000 people died and another 300 million people were displaced. Hurricane Mitch in Central America, the flooding of China’s Yangtze River, floods in Turkey, Argentina and Bangladesh, fires in Siberia, an ice storm in New England—the list is staggering. Hurricane Katrina was only the fourth recorded Category Five hurricane to have made landfall in the United States and the seventh Category Five hurricane to have maintained that status longer than thirty hours. It was followed by another Category Five hurricane, Rita, the fourth most powerful on record, and soon after by Wilma, the strongest Atlantic hurricane ever recorded.

It has been estimated that the cost of climate-related disasters for he next 20 years will be $6-10 trillion, ten times current aid flows.

The end-of-summer Arctic sea ice area was 40% less in 2007 than in the late 1970s when accurate satellite measurements began. Climate models had not predicted such a large loss before the middle of the twenty-first century. James Hansen, widely regarded as the world’s leading climate scientist, says in Storms of My Grandchildren, “I have found no Arctic researcher who believes that sea ice will survive if the world continues with business-as-usual fossil fuel use.” The Greenland and West Antarctic ice sheets are each losing mass at more than 100 cubic kilometres per year, and sea level is rising at more than 3 centimetres per decade. Glacial shrinkage worldwide is causing flooding and lack of water in many places.

According to Michael S. Northcote, human-induced global warming threatens the collapse of whole ecosystems, from the Poles to the heart of Africa, and the extinction of up to 40% of the earth’s species.

Professor Sir Ghillean Prance is an expert in biodiversity and plant taxonomy. Formerly director of the Royal Botanical Gardens at Key, he is currently director of The Eden Project. He is responsible for introducing 450 Amazonian plant species to science. He thinks so-called ‘climate sceptics’ are “like ostriches burying their heads in the sand.”