And under International Civil Aviation Organisation regulations, any structure over 45 metres tall on a flight path or near an aerodrome must be fitted with a medium-intensity aircraft warning light.

BBC: London helicopter crash: What are the rules for pilots?

An assessment of the impacts of climatic change in Latin America and the Caribbean supported by reliable data suggests that ??climate changes during the last century have included an increase in the surface medium temperature, particularly in medium and high latitudes, and changes in precipitation quantity and intensity in several countries of the Region (Southern Brazil, Paraguay, and Argentina).

UNESCO: Climatic Change

The time required to meet the goal will depend on the level of intensity, categorized on the scale as Low impact, medium impact, or high impact.

FORBES: Now There's An App That Will Help Get Your Dogs In Shape