Humans and the biosphere

The Earth’s population was about 600 million in the early 1700s and is now above 8 billion (the book says 7.5 billion), and demand for resources and the amount of waste have grown with it. Main impacts: pollution of air, water and soil by industrial, transport and farm waste; deforestation (leading to soil erosion, disturbed water regime and species loss); the accumulation of synthetic materials such as plastic that do not break down biologically; and the loss of species much faster than natural rates. Burning coal, oil and gas increases CO2, strengthens the greenhouse effect, and the planet has warmed by more than 1.2 °C above the pre-industrial level; glaciers are melting and sea level is rising – no longer a forecast but a measured fact. The Aral Sea dried up because most of the Amu Darya and Syr Darya water was diverted for irrigation, causing salinisation and dust-salt storms; on the dry seabed a green cover is being restored by planting saxaul. Natural resources are divided into renewable (forest, soil fertility, animals) and non-renewable (minerals). Rational use means low-waste technologies, sorting and recycling waste, biological pest control and renewable energy such as solar and wind.