Mots Croisés Environmental issuesVersion en ligne Write the corresponding concept according to the definition par MARIA ALEJANDRA MARIN HERRON 1 The presence in groundwater of toxic chemicals and biological agents that exceed what is naturally found in the water and may pose a threat to human health and/or the environment. 2 A gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, CFCs, and other pollutants. 3 A change in global or regional climate patterns, in particular a change apparent from the mid to late 20th century onwards and attributed largely to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels. 4 The action of clearing a wide area of trees. 5 The presence in or introduction into the environment of a substance which has harmful or poisonous effects. 4 2 3 5 1