Global warming is a long-term trend of increasing global average temperature. We still have weather, which causes fluctuations around a rising trend line. Those who live in areas with distinct seasons are well aware of this. A new season brings a much faster change than global warming does. The principle is basically the same. In the spring, a cold front may cool the weather a week or two. But most people realize, however, that summer is coming. The cooling period is just a skip down for a while before we get back to a rising temperature after the trend line.
Average monthly temperatures may vary from one year to the next by 5-6 degrees. This is weather variation. Global average temperature increase has roughly been 0,13° C per annum, or slightly less than 0,2° C per decade for the time being. That is the climate trend. This is why you should not confuse weather with climate. When you want to take a closer look at climate trends, you go to the baseline: the Normal, and compare average weather over at least five years to this baseline. Any period shorter than this is weather variations and not climate. –The Normal is calculated for a period of 30 years.
Temperature rise accelerates
For the last 50 years, global temperature rose at an average rate of about 0.13°C (around one-quarter degree Fahrenheit) per decade—around twice as fast as the 0.06°C per decade increase observed over the previous half-century. In the next 20 years, scientists project that global average temperature will rise by around 0.2°C (about one-third of a degree Fahrenheit) per decade (NOAA 2016).
” The average global temperature across land and ocean surface areas for 2015 was 0.90°C (1.62°F) above the 20th century average of 13.9°C (57.0°F), beating the previous record warmth of 2014 by 0.16°C (0.29°F). This is not only the highest calendar year temperature, but also the highest temperature for any 12-month period on record. ”
2015 record hot
2015 has clearly been warmer than 2014, although northern Europe has not had a particularly hot summer. The rest of the world has had an exceptionally warm period.
The 16 warmest years that have been recorded during the period between 1880 -2015, all occurred in this century, except 1998, which tied as the sixth warmest. (National Oceanic and Atmospheric Administration, 2016)
BBC (2016) Six graphics that explain climate change
According to NASA (2016) , “the Earth’s climate has changed throughout history. Just in the last 650,000 years there have been seven cycles of glacial advance and retreat, with the abrupt end of the last ice age about 7,000 years ago marking the beginning of the modern climate era — and of human civilization. Most of these climate changes are attributed to very small variations in Earth’s orbit that change the amount of solar energy our planet receives. The current warming trend is of particular significance because most of it is very likely human-induced and proceeding at a rate that is unprecedented in the past 1,300 years.1
Earth-orbiting satellites and other technological advances have enabled scientists to see the big picture, collecting many different types of information about our planet and its climate on a global scale. This body of data, collected over many years, reveals the signals of a changing climate”.
Earth’s 2015 surface temperatures were the warmest since modern record keeping began in 1880, according to independent analyses by NASA and the National Oceanic and Atmospheric Administration (NOAA). Globally-averaged temperatures in 2015 shattered the previous mark set in 2014 by 0.23 degrees Fahrenheit (0.13 Celsius). Only once before, in 1998, has the new record been greater than the old record by this much.
This color-coded map displays a progression of changing global surface temperature anomalies from 1880 through 2015. Higher than normal temperatures are shown in red and lower then normal termperatures are shown in blue. The final frame represents the global temperatures 5-year averaged from 2011 through 2015. Scale in degree Celsius.
“Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased” (IPCC the physical science 2013).
97% of Experts Agree (Huffington Post May 2017)
Climate change: Is your opinion informed by science? Take our quiz! (Christian Science Monitor)
- What’s in a name? Weather, global warming and climate change (NASA)
- What is global warming? (National Geographic)
- Tropospheric Warming Over The Past Two Decades (Nature, May 2017)
- Climate scientists just debunked deniers’ favorite argument (June 2017)
- 2016: one of the warmest two years on record (Met office Jan 2017)
- Infographic: February 2017 U.S. Record Temperatures (May 2017)
- IPCC: Climate Change 2013: The Physical Science Basis (Video)
- Science made easy – take the dog for a walk. The difference between climate and weather(Video)
- Is climate change caused by human activity? (Met office)
- National Research Council: Climate change: evidence, impacts and choices (NRC)
- Science publishes new NOAA analysis: Data show no recent slowdown in global warming
- Last 5 Years Hottest on Record, Human Footprint ‘Increasingly Visible’ (Nov 2016)
- 2016 will be the hottest year on record, UN says (Nov 2016)
- Heat records have become the new normal (Nov 2016)
- The 10 hottest years on record
- Responsible scientists on global warming (Sept 2016)
- Heated debates ignore an overheating planet (Oct 2016)
- An Open Letter Regarding Climate Change From Concerned Members of the U.S. National Academy of Sciences (Sept 2016)
- Royal Society: Are climate changes of a few degrees a cause for concern?
- Recalculating the Climate Math. The numbers on global warming are even scarier than we thought (Sept 2016)
- Ten Clear Indicators Our Climate Is Changing
- Nasa: Earth is warming at a pace ‘unprecedented in 1,000 years’ (Aug 2016)
- Study: Earth’s Roughly Warmest in About 100,000 Years (Sept 2016)
- Earth ‘Locked Into’ Temperatures Not Seen in 2 Million Years
- Three Ways Climate Deniers Cherry-Pick Facts about Climate Change
- The True Scientific Consensus on Anthropogenic Global Warming
- Science museum: Climate Science Info Zone
- Short Answers to Hard Questions About Climate Change
- The Earth is warming up! 2 °C is a limit that we cannot cross
- Climate disruption in overdrive: submerged cities and melting that “feeds on itself”
- Time magazine got global warming right in 2006: “Be worried. Be very worried” (March 2016)
- Bill Nye vs. Sarah Palin on Climate Change: Who Do You Believe? (April 2016)
- Bill Nye: Why I’m Taking Climate Deniers Head On: Carbon dioxide has an enormous effect on planetary temperatures.
- Burning All Fossil Fuels Would Lead to a 17 C Rise in Arctic Temperatures (May 2016)
- How Scientists Know Climate Change Is Happening
- Romm, J. (2016) One Fact About Climate Change That’s Worth Repeating
- Romm, J. (2016) Sorry Deniers, Even Satellites Confirm Record Global Warming. The planet just had its hottest 12 months on record
- The ‘best available science’ to inform 1.5 °C policy choices
- The Earth is warming at scary rates, and this GIF proves it
- Climate Change Cartoons – Must I Draw You A Picture?
- Elon Musk’s Unbelievably Simple 12-minute Killer Break Down on Climate Change
- Climate Inaction Figures: They Distort Facts, Twist Logic and Reject Science
- A world at war: We’re under attack from climate change—and our only hope is to mobilize like we did in WWII.
- Soaring Temperatures Will Make It Too Hot to Work, UN Warns (July 2016) (Bloomberg)
- First Half of 2016 Blows Away Temperature Records
- It’s Official: August Was the 16th Consecutive Record-Breaking Hottest Month (sept 2016)
- Bill Nye Destroys Climate Change Conspiracy Theories
- Who’s Driving Climate Denial? Big Companies and Conservative Media
- Michael Mann’s Hotlist of the 9 Most Prominent Climate Deniers
- Ocean Warming Is ‘Greatest Hidden Challenge of Our Generation’
- Greenland’s receding icecap to expose top-secret US nuclear project
- UNFCCC: UN climate change newsroom
- Here Are All the Climate Records Earth Shattered Last Year (Sept 2016)
- We’re Past the Point of No Return for Climate Change
Earth is in the danger zone, and every day we burn fossil fuels brings it closer to destruction. (Oct 2016)
- Broken records define the climate crisis (Oct 2016)
- Humanity Has Entered New Climate Reality Era (WMO Oct 2016)
- Uncovered: Fossil Fuel Industry Has Back-Door Access to U.N. Climate Talks
- 7 Key Scenes in Leonardo DiCaprio’s Climate Film ‘Before the Flood’
- Recalculating the Climate Math. The numbers on global warming are even scarier than we thought. (Nov 2016)
- President Obama: Climate Change Is an ‘Immediate Risk to Our National Security’ (Nov 2016)
- Last 5 Years Hottest on Record, Human Footprint ‘Increasingly Visible’ (Nov 2016)
- China minister confirms Beijing is not behind climate ‘hoax’ (Nov 2016)
- Bob Rich: There IS no global warming?
- The Weather Channel to Breitbart: ‘Earth Is Not Cooling, Climate Change Is Real’ (Dec 2016)
- World on track for 3C of warming under current global climate pledges, warns UN (Dec 2016)
- It Was Hot in 2016 And It Will Be Almost As Hot Again Next Year (Dec 2016)
- NOAA challenged the global warming ‘pause.’ Now new research says the agency was right (Jan 2017)
- Already Debunked Global Warming ‘Hiatus’ Gets Another Dunking (Jan 2017)
- Norge fra 1900 til i dag -Vær og klima i Norge har variert stort i gjennom historien
- NOAA: Study: Global Warming Hiatus Attributed to Redistribution
- Two Top TV Mets Address Climate Change A challenge and a response on TV weathercasters’ ‘responsibility’ to address climate change science … and background to help them do so (Jan 2017)
- Identifying Fake News: An Infographic and Educator Resources
- The First Climate Model Turns 50, And Predicted Global Warming Almost Perfectly (March 2017)
- Facts And Evidence Matter In Confronting Climate Crisis
- Fakery 2: More Funny Finances, Free Of Tax
- GISS Surface Temperature Analysis (GISTEMP) Frequently Asked Questions (FAQ)
- We aren’t doomed by climate change. Right now we are choosing to be doomed
- Scientists Solve Climate Hiatus ‘Puzzle of the Century’: So Now What? (July 2017)
|Home||Chapter 1||1. The natural Greenhouse effect|
|Chapter 2||2. Global Warming|
|2.1 Authoritative sources|
|2.2 The Sun?|
|2.4 Winter is cold?|
|2.5 Mitigation and adaptation|
|Chapter 3||3. Impacts|