"In 1992, more than 1,700 eminent scientists, including 104 Nobel prizewinners, signed the "World Scientists' Warning to Humanity", which included this urgent warning: "No more than one or a few decades remain before the chance to avert the threats we now confront will be lost and the prospects for humanity immeasurably diminished." 

The document concluded that environmentally damaging activity must be brought under control and the integrity of Earth's ecosystems protected.

The sooner we act, the easier it will be to overcome these difficult challenges. Every year that we stall makes it more costly and challenging, with increasing negative impacts on humans and our environment. There are signs of hope. Many countries — as well as cities, states and provinces — are taking global warming seriously and are working to reduce emissions and shift to cleaner energy sources. Some world leaders are even questioning our current paradigm, where the economy is made a priority above all else.
 Surely it must be subordinate to a rich, diverse ecosphere that sustains all life. Let's hope this year ushers in a new way of living on and caring for our planet."