Owing to unreasonable behaviour of Man there is a real danger of environmental disaster. There are many reasons for this, chiefly widening of the hole in the ozone layer over the Arctic and constant destruction of the atmospheric ozone layer as a whole. In spite of many efforts aimed at reducing production and use of substances decomposing ozone, depletion of the ozone layer proceeds three times faster compared with earlier projections. The depletion of ozone results chiefly from man-made effects: deforestation and forest dieback, also outside the tropical zone. Massive destruction of forests results in decreased production of oxygen and resin but can also alter climate.