Scientists have known about climate change for almost two hundred years and the major miles related to climate science are as under

1712 - British ironmonger Thomas Newcomen invents the first widely used steam engine, paving the way for the Industrial Revolution and industrial scale use of coal.

1800 - World population reaches one billion

1824 - French physicist Joseph Fourier describes the Earth's natural "greenhouse effect

1861 - Irish physicist John Tyndall shows that water vapour and certain other gases create the greenhouse effect.

1896 - Swedish chemist Svante Arrhenius concludes that industrial-age coal burning will enhance the natural greenhouse effect. calculated that cutting CO₂ in the atmosphere by half could lower the temperature in Europe by 4-5°C . A colleague of Arrhenius, Arvid Högbom, thought it might be worth looking at the CO emitted by factories too, not just volcanoes and natural carbon sinks like trees or oceans.

1900 - Knut Angstrom, a Swedish, discovers that even at the tiny concentrations found in the atmosphere, CO2 strongly absorbs parts of the infrared spectrum. Although he does not realise the significance, Angstrom has shown that a trace gas can produce greenhouse warming.

1927 - Carbon emissions from fossil fuel burning and industry reach one billion tonnes per year.

1938 - Guy Callendar , a British engineer using records from 147 weather stations around the world, records that temperatures & showed that it had risen over the previous century. He also noted that CO2 concentrations had increased over the same period and suggested this caused the warming. The "Callendar effect" was dismissed by meteorologists at that time.

1955 - Gilbert Plass, an US researcher,  using a new generation of equipment including early computers, analysed in detail the infrared absorption of various gases. He concludes that doubling CO2 concentrations would increase temperatures by 3-40C.

1957 - Roger Revelle, an US oceanographer and Hans Suess, a chemist showed that seawater will not absorb all the additional CO2 entering the atmosphere.

1957 was also the International Geophysical Year which further provided support to Dr Charles D. Keeling’s project measuring the concentration of carbon dioxide in the atmosphere.

1958 - Charles David (Dave) Keeling developed an equipment and measured systematic atmospheric CO2 at Mauna Loa in Hawaii and in Antarctica. Within four years, the project - which continues today - provides the first unequivocal proof that CO2 concentrations are rising. The graph of the resulting data is known as the Keeling Curve

1960 - Human population reaches three billion.

1965 - A US President's Advisory Committee panel warns that the greenhouse effect is a matter of "real concern".

1972 - First UN environment conference, in Stockholm. Climate change hardly registers on the agenda, which centres on issues such as chemical pollution, atomic bomb testing and whaling. The United Nations Environment Programme (UNEP) is formed as a result.

1975 - Human population reaches four billion.

1975 - US scientist Wallace Broecker puts the term "global warming" into the public domain in the title of a scientific paper.

1987 - Human population reaches five billion

1987 - Montreal Protocol agreed, restricting chemicals that damage the ozone layer. Although not established with climate change in mind, it has had a greater impact on greenhouse gas emissions than the Kyoto Protocol.

1988 - Intergovernmental Panel on Climate Change (IPCC) formed to collate and assess evidence on climate change.

1989 - UK Prime Minister Margaret Thatcher - possessor of a chemistry degree - warns in a speech to the UN that "We are seeing a vast increase in the amount of carbon dioxide reaching the atmosphere. The result is that change in future is likely to be more fundamental and more widespread than anything we have known hitherto." She calls for a global treaty on climate change.

1989 - Carbon emissions from fossil fuel burning and industry reach six billion tonnes per year.

1990 - IPCC produces First Assessment Report. It concludes that temperatures have risen by 0.3-0.6C over the last century, that humanity's emissions are adding to the atmosphere's natural complement of greenhouse gases, and that the addition would be expected to result in warming.

1992 - At the Earth Summit in Rio de Janeiro, governments agree the United Framework Convention on Climate Change. Its key objective is "stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system". Developed countries agree to return their emissions to 1990 levels.

1995 - IPCC Second Assessment Report concludes that the balance of evidence suggests "a discernible human influence" on the Earth's climate. This has been called the first definitive statement that humans are responsible for climate change.

1997 - Kyoto Protocol agreed. Developed nations pledge to reduce emissions by an average of 5% by the period 2008-12, with wide variations on targets for individual countries. US Senate immediately declares it will not ratify the treaty.

1998 - Strong El Nino conditions combine with global warming to produce the warmest year on record. The average global temperature reached 0.52C above the mean for the period 1961-90 (a commonly used baseline).

1998 - Publication of the controversial "hockey stick" graph indicating that modern-day temperature rise in the northern hemisphere is unusual compared with the last 1,000 years. The work would later be the subject of two enquiries instigated by the US Congress.

1999 - Human population reaches six billion.

2001 - President George W Bush removes the US from the Kyoto process.

2001 - IPCC Third Assessment Report finds "new and stronger evidence" that humanity's emissions of greenhouse gases are the main cause of the warming seen in the second half of the 20th Century.

2005 - The Kyoto Protocol becomes international law for those countries still inside it.

2005 - UK Prime Minister Tony Blair selects climate change as a priority for his term as chair of the G8 and president of the EU.

2006 - The Stern Review concludes that climate change could damage global GDP by up to 20% if left unchecked - but curbing it would cost about 1% of global GDP.

2006 - Carbon emissions from fossil fuel burning and industry reach eight billion tonnes per year.

2007 - The IPCC's Fourth Assessment Report concludes it is more than 90% likely that humanity's emissions of greenhouse gases are responsible for modern-day climate change.

2007 - The IPCC and former US vice-president Al Gore receive the Nobel Peace Prize "for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change".

2007 - At UN negotiations in Bali, governments agree the two-year "Bali roadmap" aimed at hammering out a new global treaty by the end of 2009.

2008 - Half a century after beginning observations at Mauna Loa, the Keeling project shows that CO2 concentrations have risen from 315 parts per million (ppm) in 1958 to 380ppm in 2008.

2008 - Two months before taking office, incoming US president Barack Obama pledges to "engage vigorously" with the rest of the world on climate change.

2009 - China overtakes the US as the world's biggest greenhouse gas emitter - although the US remains well ahead on a per-capita basis.

2009 - Computer hackers download a huge tranche of emails from a server at the University of East Anglia's Climatic Research Unit and release some on the internet, leading to the "ClimateGate" affair.

2009 - 192 governments convene for the UN climate summit in Copenhagen with expectations of a new global agreement high; but they leave only with a controversial political declaration, the Copenhagen Accord.

2010 - Developed countries begin contributing to a $30bn, three-year deal on "Fast Start Finance" to help them "green" their economies and adapt to climate impacts.

2010 - A series of reviews into "ClimateGate" and the IPCC ask for more openness, but clear scientists of malpractice.

2010 - The UN summit in Mexico does not collapse, as had been feared, but ends with agreements on a number of issues.

2011 - A new analysis of the Earth's temperature record by scientists concerned over the "Climate Gate" allegations proves the planet's land surface really has warmed over the last century.

2011 - Human population reaches seven billion.

2011 - Data shows concentrations of greenhouse gases are rising faster than in previous years.

2012 - Arctic sea ice reaches a minimum extent of 3.41 million sq km (1.32 million sq mi), a record for the lowest summer cover since satellite measurements began in 1979.

2013 - The Mauna Loa Observatory on Hawaii reports that the daily mean concentration of CO2 in the atmosphere has surpassed 400 parts per million (ppm) for the first time since measurements began in 1958.

2013 - The first part of the IPCC's fifth assessment report says scientists are 95% certain that humans are the "dominant cause" of global warming since the 1950s.

2015- The year is the warmest on record & drought plague many areas of the planet.

2015- The Paris Climate Accord is sined by 196 countries calling for voluntary but monitorable and enforceable reductions in CO2 of between 40 % and 70% by 2050 compared to 2010, an agreement to recommit to higher levels of reductions every five years with an aim to keep temperature rise to 1.50C, a commitment to sustainable development.


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