| Higher levels of water pollution in the air during the | | | | the particles of lead, rejected in large part by human |
| years 1970 and 1980 is likely to lead to inhibition of | | | | activity, had not promoted the formation of clouds. |
| global temperature increases to a certain extent | | | | Indeed, the presence of lead allows the formation of |
| today, almost a full effect greenhouse is kicking in, as | | | | clouds where the air is not normally quite wet and |
| there was a continued decrease in the rate of | | | | cold. Sunlight would be more thoughtful on the |
| anthropogenic emissions of lead in the last 20 years. | | | | surface of these clouds, which would mitigate the |
| As shown in a study published in Nature Geosciences, | | | | greenhouse effect in the years 1970-1980, before |
| the lead pollution was to reduce the impact of | | | | the mass consumption of unleaded petrol. |
| greenhouse gases on global warming. The particles of | | | | "To some extent this has probably led to a |
| lead nurtures the formation of clouds which become | | | | slowdown of rising global temperatures, whereas |
| effective "umbrella". | | | | today, almost all of the greenhouse gases are |
| Investigators from Switzerland, Germany and the | | | | starting to act," says Joachim Curtius, a professor at |
| United States "captured" a few clouds on the | | | | the University Frankfurt, Germany. |
| mountains, and compare it with artificially created in | | | | This study did not aim to enhance the lead pollution |
| the laboratory. | | | | which is extremely harmful, but it helps to explain the |
| It showed that emissions of greenhouse gases could | | | | acceleration of climate change in recent years. |
| have had much greater effects on global warming if | | | | |