humans are using 30% more resources than the Earth can replenish each year, which is leading to deforestation, degraded soils, polluted air and water, and dramatic declines in numbers of fish and other species
we are running up an ecological debt of $4tr (£2.5tr) to $4.5tr every year
populations and consumption keep growing faster than technology finds new ways of expanding what can be produced from the natural world
by 2030, if nothing changes, mankind would need two planets to sustain its lifestyle
Sir David King, the British government's former chief scientific adviser, said: "We all need to agree that there's a crisis of understanding, that we're removing the planet's biodiverse resources at a rate which is as fast if not faster than the world's last great extinction."
50 countries are already experiencing "moderate to severe water stress on a year-round basis"
27 countries are "importing" more than half the water they consume - in the form of water used to produce goods from wheat to cotton - including the UK, Switzerland, Austria, Norway and the Netherlands.
A person's footprint ranges vastly across the globe, from eight or more "global hectares" (20 acres or more) for the biggest consumers in the United Arab Emirates, the US, Kuwait and Denmark, to half a hectare in the Democratic Republic of Congo, Haiti, Afghanistan and Malawi.
The global average consumption was 2.7 hectares a person, compared with a notional sustainable capacity of 2.1 hectares.
Across generations people construct a conception of what is environmentally normal based on the natural world encountered in childhood
with each ensuing generation, the amount of environmental degradation increases, but each generation tends to take that degraded condition as the non-degraded condition, as the normal experience
None of us living today have experienced certain forms of interaction with nature that were common even one or two hundred years ago.
Today the Highlands of Scotland are one of the most deforested lands in the world. Perhaps equally disturbing, the Scots of today, according to Hand, have virtually no conception of a forest, of its ecological vastness and beauty.
environmental problems can be understood as equally serious across generations even while the problems worsen.
Prized as a "natural water tower", the forest has also been the target for aggressive clearance and timber logging in recent decades and its size has been cut by at least 40%.
Research by the Kenya Forest Research Institute (KEFRI) and the UN Environment Programme (UNEP) estimates the economic benefit of the forest to be more than $1.3bn per year.
Bordering the trees are some of Kenya's largest tea plantations - tea is one of the country's key exports and the research calculates that it benefits from the forest to the tune of $163m a year.
The study calculates that the Mau Forest's value to the electricity sector is $131.6m.
This blaze of lurid colour helps to make tourism one of Kenya's biggest earners, and the study reckons this industry receives $65 million in benefits from the forest.
Further services provided by the forest include an estimated $89million in storing carbon, $98million in controlling soil erosion and $21million in support for fisheries.