In generally, the phrase climate change describes the change in weather patterns when that change lasts for an extended period of time.
But in the last decades we got accustomed to accept the term as synonymous to global warming and referring to the alternation in global climate resulting from the damaging effect of the increasing levels of atmospheric carbon dioxide released from industry and agriculture.
In 1854, the United States Magazine of Science, Art, Manufactures, Agriculture, Commerce and Trade was the first English source to publish an explanation on the climate change triggered by human activity, and in particular by agriculture: “Some have ascribed these climate changes to agriculture—the cutting down the dense forests—the exposure of the upturned soil to the summer sun, and the draining of the great marshes.”
The perceptive of climate changes attributed to emissions of carbon dioxide was first described by The Hammond Times in 1957: “This continued pouring forth of waste gases may upset the rather delicate carbon dioxide balance in the earth’s general atmosphere and..a large scale global warming, with radical climate changes may result.”
The greenhouse effect was known since the 1820s, but its scientific description was developed in the 1930s. And while the usage of the phrase global warming can be traced back at least to 1952 when The San Antonio Express-News reported on: “’Scientists who are studying global warming trends point out that not a single iceberg was sighted last year south of Parallel 46”, it is largely believed that the first scientist to name the human-caused climate change “global warming,” is Wallace Broecker of Columbia University in his 1975 science article: “Climatic Change: Are We on the Brink of a Pronounced Global Warming?”
The first warning that the greenhouse effect is a matter of real concern came from a US President’s Advisory Committee panel in 1965, followed by the forming of the Intergovernmental Panel on Climate Change in 1988, to the 1992 Earth Summit in Rio de Janeiro, where governments agree the United Framework Convention on Climate Change (the current Paris agreement, to curb climate change, is an agreement within the UNFCCC).
In 1997, the US Senate did not ratify the Kyoto Protocol where nations pledged to reduce emissions by an average of 5% by the period 2008-12, and 20 years later Donald Trump (who has called climate change ‘a hoax’) withdrew the US from the Paris agreement on climate change, declaring it unfair to the United States and bad for business, yet stating that his administration would begin negotiations either to re-enter the Paris accord or to have a new agreement.
As of June 2017, 195 UNFCCC members have signed the agreement, 148 of which have ratified it, committing to keeping rising global temperatures well below 2C above pre-industrial levels and “endeavour to limit” them even more, to 1.5C, where rich countries pledge to help poorer nations switch to renewable energy by providing “climate finance”.
How do we know that climate change is real? Earth-orbiting satellites have enabled scientists to collect information about our planet and its climate on a global scale. We have scientific evidence for global temperature and see levels rises, shrinking ice sheets and retreating glaciers, ocean acidification, polluted areas and extreme events; and that there is more than 95% probability that the reason behind the rapid climate change observed in the last century is, indeed, the human activity.