History is laden with those false horrendous claims.  Recall these false alarms:

• Thomas Robert Malthus -- one of the earliest doom & gloom failed theories
• Paul Ehrlich -- “Population will inevitably and completely outstrip whatever small increases in food supplies we make,”
• Barry Commoner -- “We are in an environmental crisis which threatens the survival of this nation, and of the world as a suitable place of human habitation,”
• No more beef, instead pushing society to be eating bugs
• Al Gore's 20 ft of rising sea levels

Even the Huffington Post has been critical of Gore's failing gloom & doom predictions    Click Here  

In the climate field, there's multiple failed predictions.  Here's a cartoon illustration: