I was going to wait but I recently watched the film of Dan Brown's book "Inferno" and was really, really disappointed.
SPOILER ALERT
The whole point of the book was that the "plague" that the "mad scientist" successfully releases turns out not to kill people but to alter their DNA so as to render a random third of the population sterile and thus limit our numbers relatively humanely.
In the film it is a killer plague but our heroes prevent its release just in time so that we can continue to breed our species and the planet to death. (Sorry, that's a bit dramatic, the planet will be fine and enough creatures will survive to carry on evolution's great experiment just without us and a lot of other species.)
Well we're almost at the seven and a half billion humans point, so here goes..............
The average human now consumes 100,000 tonnes of fresh water, 720 tonnes of metals, 750 tonnes of topsoil and burns 5.4 billion BTUs of (mostly fossil) energy. This is 10 times more than our grandparents.
It takes the Earth 18 months to regenerate what humans consume in a year.
Humans are presently engaged in the greatest act of extermination of other species by a single species, probably since life on Earth began. We destroy an estimated 30,000 species a year. In the last 45 years we have killed off 58 per cent of the world’s large animals.
We contaminate the atmosphere with 50 billion tonnes of greenhouse emissions a year for a total to date of 2 trillion tonnes. This risks accelerated planetary warming reaching 4-5°C by 2100. Under such conditions there will be widespread famines, threatening all of the, by then, 10 billion members of the enlarged human population.
We contaminate the biosphere with 250 billion tonnes of chemicals and wastes each year. These have spread all round the planet from the deep oceans to the highest mountains and most remote regions. The World Health Organisation states “An estimated 12.6 million people died as a result of living or working in an unhealthy environment in 2012 – nearly 1 in 4 of total global deaths”.
We contaminate the oceans with megatonnes of nutrients, CO2 and toxins. This is causing acidification, the collapse of ocean food chains and the spread of 470+ ‘dead zones’ around the planet. Ninety per cent of world fisheries are maxed out.
Global soil loss due to agriculture and development amounts to 75 billion tonnes a year and scientists warn we could run out of topsoil within half a century.
One in nine of us are starving. That's 795 million people.
Acute water scarcity faces 4 billion humans at least one month a year; a UN report warns that at present rates of use world demand for freshwater will exceed supply by 40 per cent by 2030.
At the time of writing the world's human population stood at 7,487,326,251
Where's a Mad Scientist when you need one?