2.1 Authoritative sources

nasa logo


On Earth, human activities are changing the natural greenhouse. Over the last century the burning of fossil fuels like coal and oil has increased the concentration of atmospheric carbon dioxide (CO2). This happens because the coal or oil burning process combines carbon with oxygen in the air to make CO2. To a lesser extent, the clearing of land for agriculture, industry, and other human activities have increased concentrations of greenhouse gases.  http://climate.nasa.gov/causes/


logo_noaaNational Climatic Data Center (NCDC)

…the most essential indicators of Earth’s changing climate continued to reflect trends of a warming planet, with several markers—such as rising land and ocean temperature, sea levels, and greenhouse gases—setting new records  https://www.ncdc.noaa.gov/cag/global/time-series/

pdflogo-enEuropean Environment Agency (EEA)

Climate change is happening now: temperatures are rising, rainfall patterns are shifting, glaciers and snow are melting, and the global mean sea level is rising. We expect that these changes will continue, and that extreme weather events resulting in hazards such as floods and droughts will become more frequent and intense. Impacts and vulnerabilities for nature, the economy and our health differ across regions, territories and economic sectors in Europe. It is very likely that most of the warming since the mid -20th century is due to the observed increase in greenhouse gas (GHG) concentrations as a result of emissions from human activities. The global temperature has risen by about 0.8 ºC over the past 150 years, and is projected to increase further. Exceeding an increase of 2 °C above pre-industrial temperatures raises the risk of dangerous changes for global human and natural systems. http://www.eea.europa.eu/


wb logoWorld Bank

All development is now taking place in a world shaped by climate. Climate change is happening now and impacting countries and people, with the poor the hardest hit. The World Bank Group is concerned that without bold action now, the warming planet threatens to put prosperity out of reach of millions and roll back decades of development
World Bank branch to prefer private banks that exit coal


un-emblemUnited Nations

Climate change will amplify existing risks and create new risks for natural and human systems. Risks are unevenly distributed and are generally greater for disadvantaged people and communities in countries at all levels of development.
Many aspects of climate change and associated impacts will continue for centuries, even if anthropogenic emissions of greenhouse gases are stopped. The risks of abrupt or irreversible changes increase as the magnitude of the warming increases.


ccc_logoThe Committee on Climate Change (the CCC)

The Committee on Climate Change (the CCC) is an independent, statutory body established under the Climate Change Act 2008. Our purpose is to advise the UK Government and Devolved Administrations on emissions targets and report to Parliament on progress made in reducing greenhouse gas emissions and preparing for climate change. In fulfilling this role our focus is to Provide independent advice to Government on setting and meeting carbon budgets and preparing for climate change; Monitor progress in reducing emissions and achieving carbon budgets;  Conduct independent analysis into climate change science, economics and policy and Engage with a wide range of organisations and individuals to share evidence and analysis


It is extremely likely that human activities caused more than half of the observed increase in GMST from 1951 to 2010. This assessment is supported by robust evidence from multiple studies using different methods. Observational uncertainty has been explored much more thoroughly than previously and the assessment now considers observations from the first decade of the 21st century and simulations from a new generation of climate models whose ability to simulate historical climate has improved in many respects


IEA logo (1)International Energy Agency (IEA)

Modern societies increasingly depend on reliable and secure energy supplies for economic growth and community prosperity. Maintaining reliable and secure energy supplies while rapidly decarbonising power systems is a key challenge for countries throughout the world. The IEA can help member countries develop their energy policy so they can effectively address climate change.
IEA’s Message For Youth on Climate Change   |     http://www.iea.org/topics/climatechange/



OECD climate change work is focusing on how to move countries to a low-carbon and climate resilient pathway, and how to improve the effectiveness of the global climate regime .  Governments must stop subsidising fossil fuels because it is the “greatest misallocation of resources,” says Ángel Gurría, Secretary-General of the Organisation for Economic Co-operation and Development (OECD) http://www.oecd.org/environment/cc/


IMF logoInternational Monetary Fund (IMF)

…energy subsidies amount to a staggering
$ 1.9 trillion worldwide—the equivalent
of 2½ percent of global GDP, or 8 percent of government revenues.      https://www.imf.org/external/np/sec/pr/2013/pr1393.htm

US Intelligence Community
World Wide Threat Assessment

“The impacts of the long-term trends toward a warming climate, more air pollution, biodiversity loss, and water scarcity are likely to fuel economic and social discontent—and possibly upheaval—through 2018.
 The past 115 years have been the warmest period in the history of modern civilization, and the past few years have been the warmest years on record. Extreme weather events in a warmer world have the potential for greater impacts and can compound with other drivers to raise the risk of humanitarian disasters, conflict, water and food shortages, population migration, labor shortfalls, price shocks, and power outages. Research has not identified indicators of tipping points in climate-linked earth systems, suggesting a possibility of abrupt climate change.”. https://www.dni.gov/files/documents/Newsroom/Testimonies/2018-ATA—Unclassified-SSCI.pdf


who logoWorld Health Organisation

Climate change affects the social and environmental determinants of health – clean air, safe drinking water, sufficient food and secure shelter.  Between 2030 and 2050, climate change is expected to cause approximately 250 000 additional deaths per year, from malnutrition, malaria, diarrhoea and heat stress.    http://www.who.int/mediacentre/factsheets/fs266/en/


world heritage logoWorld Heritage and climate change

World Heritage properties  harbour options for society to mitigate and adapt to climate change through the ecosystem benefits, such as water and climate regulation, that they provide and the carbon that is stored in World Heritage forest sites. Cultural heritage, on the other hand, can convey traditional knowledge that builds resilience for change to come and leads us to a more sustainable future.

World Heritage properties serve as climate change observatories to gather and share information on applied and tested monitoring, mitigation and adaptation practices. The global network of World Heritage also helps raise awareness on the impacts of climate change on human societies and cultural diversity, biodiversity and ecosystem services, and the world’s natural and cultural heritage. http://whc.unesco.org/en/climatechange/


unesco logo_enUNESCO and Climate Change

The UNESCO Climate Change Education Clearinghouse contains a large number of links to documents and materials from non-profit organizations, research institutions, government agencies and other sources outside the UN system.


fao logoFood and Agriculture Organisation

Climate change is a fundamental threat to global food security, sustainable development and poverty eradication. Agriculture, including the forestry and fisheries sectors, must adapt to the impacts of climate change and improve the resilience of food production systems in order to feed a growing population.That is why it must be addressed as an integral part of the overall development agenda. http://www.fao.org/climate-change/en/


unhcr logoUN High Commissioner for Refugees (UNHCR)

As more and more people live in locations highly vulnerable to disasters and other climate change impacts, planned relocation will be one response States may take to protect affected communities. It is important for States and practitioners to draw lessons from past experiences to ensure that future movements are initiated, planned, and carried out in a rights-respecting manner and lead to the most positive outcomes possible for those involved. http://www.unhcr.org/54082cc69.html


iucnInternational Union for the Conservation of Nature (IUCN)

Climate change is one of the most pressing environment and development challenges confronting humanity today. IUCN engages on this issue from multiple perspectives, from assessing the risks that climate change poses to advancing practical nature-based solutions centred on better conservation, management and restoration of natural ecosystems.

Healthy ecosystems such as forests, oceans and wetlands make a critical and well-known contribution to climate change mitigation by absorbing and storing carbon. They also help vulnerable communities, especially those who depend on natural resources, to better adapt and become more resilient to the adverse effects of climate change. At the same time, they provide a number of other valuable economic, social and environmental benefits.


wwf logoWorld Wildlife Fund (WWF)

As climate change continues, dangerous weather events are becoming more frequent or severe in the US and around the globe. Through its Earth Hour City Challenge, WWF is recognizing and supporting cities’ transition toward 100 percent renewable energy and take actions to address local climate.  http://www.worldwildlife.org/initiatives/climate
Our planet is warming. Here’s what’s at stake if we don’t act now (2018)


cru logoClimate Research Institute

The aim of the Climatic Research Unit (CRU) is to improve scientific understanding in past climate history and its impact on humanity; the course and causes of climate change during the present century and prospects for the future  http://www.cru.uea.ac.uk/information-sheets


casEarth institute, Columbia university

We are working to halt the global march toward catastrophic climate change via a strategy that leads as rapidly as possible to a near-universal carbon fee on fossil fuels.

Geophysical scientists presumed that as the reality of human-caused climate change became apparent, governments would be influenced to affect energy policies so as to mitigate long-term climate change. Reality is proving to be quite different. The science of climate change has become clearer during the past several years, revealing that continued “business-as-usual” burning of fossil fuels will result in certain large-scale climate change this century and beyond.

Yet governments are allowing and even encouraging, often with direct or indirect subsidies, a dash for ever more fossil fuels, including some of the most carbon intensive fuels, such as tar sands and tar shale, with mining activity in places and with methods that cause local and global pollution. The science is clear enough to the relevant scientific community: we cannot go down that path without guaranteeing that we leave youth and coming generations a more desolate planet, with continuing, growing repercussions.


nap logoNational Academies Press  (NAP)

Climate is changing, forced out of the range of the past million years by levels of carbon dioxide and other greenhouse gases not  in the Earth’s atmosphere for a very, very long time. Lacking action by the world’s nations, it is clear that the planet will be warmer, sea level will rise, and patterns of rainfall will change. But the future is also partly uncertain — there is considerable uncertainty about how we will arrive at that different climate. Will the changes be gradual, allowing natural systems and societal infrastructure to adjust in a timely fashion? Or will some of the changes be more abrupt, crossing some threshold or “tipping point” to change so fast that the time between when a problem is recognized and when action is required shrinks to the point where orderly adaptation is not possible? http://www.nap.edu/catalog/18373/abrupt-impacts-of-climate-change-anticipating-surprises
National Academy Press: Advancing the Science of Climate Change

national geographic

Record heat, melting ice, and rising seas show how climate change is affecting us.
But there’s new hope we can cool the planet. Here’s how.

National Geographic has many excellent educational sources on climate change and global warming


royal socRoyal Society

It has become fashionable in some parts of the UK media to portray the scientific evidence that has been collected about climate change and the impact of greenhouse gas emissions from human activities as an exaggeration.

Earth’s average surface air temperature has increased by about 0.8 °C (1.4 °F) since 1900, with much of this increase taking place since the mid-1970s. A wide range of other observations (such as reduced Arctic sea ice extent and increased ocean heat content) and indications from the natural world (such as poleward shifts of temperature-sensitive species of fish, mammals, insects, etc.) together provide incontrovertible evidence of planetary-scale warming. The Royal Society: Climate Change: Evidence & Causes   https://royalsociety.org/policy/projects/climate-evidence-causes/ |
Climate change: catastrophe, hoax or just lukewarm? https://www.youtube.com/watch?v=8zqL6Rjacyk

aguAmerican Geophysical Union

Extensive, independent observations confirm the reality of global warming. These observations show large‐scale increases in air and sea temperatures, sea level, and atmospheric water vapor; they document decreases in the extent of mountain glaciers, snow cover, permafrost, and Arctic sea ice. These changes are broadly consistent with long‐ understood physics and predictions of how the climate system is expected to respond to human‐caused increases in greenhouse gases. The changes are inconsistent with explanations of climate change that rely on known natural influences.  http://sciencepolicy.agu.org/files/2013/07/AGU-Climate-Change-Position-Statement_August-2013.pdf


aaas_rgb_rev_croppedAmerican Association for the Advancement of Science (AAAS)

Mounting evidence suggests that climate change can lead to more frequent and more severe extreme weather events, from intense storms and floods to heat waves and droughts. A “perfect storm” of these events occurring in multiple “breadbasket” or food-producing regions can have drastic global impacts, including malnutrition, spikes in food prices, and food riots.  AAAS 2014: What we know
|  http://www.aaas.org/news/threat-weather-driven-food-shock-looms-large-scientists-warn


logo-ucsUnion of Concerned Scientists

For nearly three decades, many of the world’s largest fossil fuel companies have knowingly worked to deceive the public about the realities and risks of climate change.

Their deceptive tactics are now highlighted in this set of seven “deception dossiers”—collections of internal company and trade association documents that have either been leaked to the public, come to light through lawsuits, or been disclosed through Freedom of Information (FOIA) requests.

Each collection provides an illuminating inside look at this coordinated campaign of deception, an effort underwritten by ExxonMobil, Chevron, ConocoPhillips, BP, Shell, Peabody Energy, and other members of the fossil fuel industry.

A newly discovered email from a former Exxon employee revealed that the company was already factoring climate change into decisions about new fossil fuel extraction as early as 1981 (The Climate Deception Dossiers (2015)  http://www.ucsusa.org/global-warming/fight-misinformation/climate-deception-dossiers-fossil-fuel-industry-memos#.VtGlb_nhCM8

Union of Concerned Scientist (2018) The Disinformation Playbook
How Business Interests Deceive, Misinform, and Buy Influence at the Expense of Public Health and Safety

Union of Concerned Scientist (2018)  Fighting Misinformation. Exposing special-interest spin and inappropriate influence on policy.

Center for responsive politics: Open Secrets.org

Center for Responsive Politics is the nation’s premier research group tracking money in U.S. politics and its effect on elections and public policy. OUR VISION is for Americans to be empowered by access to clear and unbiased information about money’s role in politics and policy and to use that knowledge to strengthen our democracy. OUR MISSION is to produce and disseminate peerless data and analysis on money in politics to inform and engage Americans, champion transparency, and expose disproportionate or undue influence on public policy.  https://www.opensecrets.org/


The Met Office UK – Hadley Centre

It is now clear that man-made greenhouse gases are causing climate change. The rate of change began as significant, has become alarming and is simply unsustainable in the long-term. The Met Office UK – Hadley Centre http://www.metoffice.gov.uk/climate-change


bjerknesThe Bjerknes Centre, University of Bergen

Warm summers were experienced during Roman times, up to the 3rd century, followed by generally cooler conditions from the 4th to the 7th centuries. A generally warm medieval period was followed by a mostly cold Little Ice Age from the 14th to the 19th centuries. The pronounced warming early in the 20th century and in recent decades is well captured by the tree-ring data and historical evidence on which the new reconstruction is based.

The evidence suggests that past natural changes in summer temperature are larger than previously thought, suggesting that climate models may underestimate the full range of future extreme events, including heat waves. This past variability has been associated with large volcanic eruptions and changes in the amount of energy received from the sun. The new research finding that temperatures over the past 30 years lie outside the range of these natural variations supports the conclusions reached by the International Panel on Climate Change (IPCC) that recent warming is mainly caused by anthropogenic activity.
Bjerknes Center (2016) The current warmth in a historical perspective http://www.bjerknes.uib.no/en/article/news/current-warmth-historical-perspective 


Munich-Re-logoMunich re

Climate Change is a subject that concerns us all. .For more than 40 years, Munich Re has been dealing with climate change and the related risks and opportunities for the insurance industry. Our approach to coping with this challenge is holistic and based on the following pillars: risk assessment – insurance solutions – asset management.  http://www.munichre.com/en/group/focus/climate-change/index.html


7 NASA Selfies Show Just How Much Our Climate Is Changing: a series of pictures of Earth through the years from the U.S. National Aeronautics and Space Administration (NASA). And while some pictures could use a thousand words to make their point, these images only need four: “Our climate is changing.” http://ecowatch.com/2016/02/24/7-nasa-selfies-show-just-much-climate-changing/


logoWorld Resources Institute

Stabilizing the global climate is the greatest challenge of the 21st century. Temperatures have exceeded global annual averages for 38 consecutive years. The impacts are being felt all around the world.

Extreme weather events are becoming more frequent and severe. Heat waves and drought plague many countries, destroying agriculture, increasing the risk of wildfires and endangering lives. Rising sea level threatens coastal communities and infrastructure by amplifying flooding and storm surge. http://www.wri.org/our-work/topics/climate


logo2Real Climate

RealClimate is a commentary site on climate science by working climate scientists for the interested public and journalists. We aim to provide a quick response to developing stories and provide the context sometimes missing in mainstream commentary. The discussion here is restricted to scientific topics and will not get involved in any political or economic implications of the science. http://www.realclimate.org/



At CICERO we provide and perform research on climate services bridging science, communication, and decision making to enable the transition to a resilient low-carbon future both in Norway and on the international level. http://www.cicero.uio.no/en


unepUnited Nations Environment Programme (UNEP)

Climate change has long-since ceased to be a scientific curiosity, and is no longer just one of many environmental and regulatory concerns. As the United Nations Secretary General has said, it is the major, overriding environmental issue of our time, and the single greatest challenge facing environmental regulators. It is a growing crisis with economic, health and safety, food production, security, and other dimensions.

Shifting weather patterns, for example, threaten food production through increased unpredictability of precipitation, rising sea levels contaminate coastal freshwater reserves and increase the risk of catastrophic flooding, and a warming atmosphere aids the pole-ward spread of pests and diseases once limited to the tropics.



Adaptation to climate change has the potential to substantially reduce many of the adverse impacts of climate change and enhance beneficial impacts—though neither without cost nor without leaving residual damage. The key features of climate change for vulnerability and adaptation are those related to variability and extremes, not simply changed average conditions  http://grida.no/



Yale Climate Connections

Listen. Watch. Read. Act



The Climate reality project

Use your voice. Let the world know the reality of climate change. Explore the actions below and get vocal with your friends, family, and community today. https://www.climaterealityproject.org/

guardianThe Guardian on Climate change

Fossil fuel use must fall twice as fast as thought to contain global warming

vaticanThe Vatican Church

1. “LAUDATO SI’, mi’ Signore” – “Praise be to you, my Lord”. In the words of this beautiful canticle, Saint Francis of Assisi reminds us that our common home is like a sister with whom we share our life and a beautiful mother who opens her arms to embrace us. “Praise be to you, my Lord, through our Sister, Mother Earth, who sustains and governs us, and who produces various fruit with coloured flowers and herbs”.

2. This sister now cries out to us because of the harm we have inflicted on her by our irresponsible use and abuse of the goods with which God has endowed her. We have come to see ourselves as her lords and masters, entitled to plunder her at will. The violence present in our hearts, wounded by sin, is also reflected in the symptoms of sickness evident in the soil, in the water, in the air and in all forms of life. This is why the earth herself, burdened and laid waste, is among the most abandoned and maltreated of our poor; she “groans in travail” (Rom 8:22). We have forgotten that we ourselves are dust of the earth (cf. Gen2:7); our very bodies are made up of her elements, we breathe her air and we receive life and refreshment from her waters.

nato assemblyNATO

The NATO Parliamentary Assembly – Fully convinced that climate change-related risks will affect international security through increased natural disasters; stress on economic, food and water security; risks to public health; internal and external migration; and resource competition;

Acknowledging that climate change-related risks are significant threat multipliers that will shape the security environment in areas of concern to the Alliance and have the potential to significantly affect NATO planning and operations;

Recognising the need to supplement climate action with efforts to strengthen the resilience of states and societies at risk through adaption measures, development and humanitarian aid, and peacebuilding and conflict prevention programmes;




Climate change is dramatically changing the world we love. It’s putting our homes, our land and our food at risk. For nearly a billion people in poverty, more extreme weather and more disasters mean more hunger.



What’s really warming the world?


nas logoThe National Academies of Sciences, Engineering, and Medicine

Using the common language of science, the U.S. National Academies of Sciences, Engineering, and Medicine work cooperatively with scientists, engineers, and medical professionals worldwide to address unprecedented challenges that threaten the health and welfare of all people, as well as the planet on which we live. The Academies’ extensive efforts in international outreach are concentrated in four main areas    Climate Change: Lines of Evidence

Climate news network 2016: Climate deniers get a reality check


List of Worldwide Scientific Organizations that Hold the Position That
Climate Change Has Been Caused by Human Action

Consensus on Consensus: 97% of the World’s Climate Scientists Say Humans Are Causing Climate Change


Home  Chapter 1 1.   The natural Greenhouse effect
Chapter 2 2.  Global Warming
2.1 Authoritative sources
2.2 The Sun?
2.3 Volcanoes?
2.4 Winter is cold?
2.5 Mitigation and adaptation
 Chapter 3 3. Impacts