Current Climate Conditions: This section also includes limited forecasting in US Navy data.
Myths vs. Facts in Global Warming: This news and analysis section addresses substance of arguments such as "global warming is a hoax", "global warming is a fiction", "global warming is created to make money for Al Gore". The main fallacy noted is that most arguments are facts out of context while others are simply false representations. When the facts pertaining to the arguments are viewed in context relevance becomes obvious. Global warming is happening and it is human caused. There is no valid evidence that can prove otherwise. False representations or facts out of context are not a proof of any kind, they are merely incorrect.
Summarizing for policy makers current understanding of climate related science and potential impacts for risk assessment.
NASA (National Aeronautics & Space Administration), GISS (Goddard Institute of Space Studies), EPA (Environmental Protection Agency), EO (Earth Observatory), Scientific Visualization, NSIDC (National Snow & Ice Data Center), NOAA (National Oceanic & Atmospheric Administration), JPL (Jet Propulsion Laboratory), NCAR (National Center for Atmospheric Research), UCAR (University Center for Atmospheric Research), NHC (National Hurricane Center), NCDC (National Climate Data Center), NAS (National Academy of Science), USGS (US Geological Survey), FS (Forestry Service)
In 1958, Director Frank Capra made a movie for Bell Labs to explain the expected effects of 'Global Warming'. This was shortly after Revelle's paper came out. Capra, was also a scientist who graduated from California Institute of Technology in 1918 and did many science films for education.
Margaret Thatcher delivered a speech in 1989 that was powerful, compelling and succinct. She accurately described the potentials for mankind in reasoned tones if we did not address global warming. Themes: Agriculture, Energy, Environment, Foreign policy (general discussions), Foreign policy (development, aid, etc), Foreign policy (International organizations), Science and technology, Transport
Editor's note: This is the official German government translation of the speech given by Chancellor Angela Merkel before the US Congress on Nov. 3, 2009. To our knowledge, Chancellor Merkel is the only (conservative) EU State Representative to address the US Congress on the critical nature of Global Warming. In her speech before the US Congress on Tuesday, German Chancellor Angela Merkel thanked the Americans for their decades-long support of Germany and for their role in helping to end the Cold War. She also reminded US politicians that the world will be looking to America and Europe in December for leadership in forging a global climate change agreement.
Aerosols are tiny particles that are capable of suspending in the atmosphere. Most come from natural means such as dust storms, volcanoes, fires, or even vegetation and sea spray (sea salt released into the atmosphere). Human activity also contributes aerosol pollution through the alteration of natural surface cover, industrial pollutants, and the burning of fossil fuels.
Antarctica is melting, not growing. In fact the ice mass is dropping at an accelerating rate due to multiple factors including accelerated glacial ice calving rates. The loss of sea based ice allows the Antarctic ice to move faster towards the ocean resulting in an increased rate of loss of the Antarctic ice.
The Antarctic Oscillation (AAO) is a measure of the pressure gradient between the polar and subpolar regions of the Southern Hemisphere. Term was introduced by Thompson and Wallace (2000).
It is important to understand that ice mass and ice extent are two entirely different animals when it comes to understanding what is happening in the Arctic. The ice mass at the North Pole is rapidly diminishing. The effects of global warming on the Arctic ice is more pronounced due to the Arctic Amplification effect.
The Arctic Oscillation (AO) is a large scale mode of climate variability, also referred to as the Northern Hemisphere annular mode. The AO is a climate pattern characterized by winds circulating counterclockwise around the Arctic at around 55°N latitude.
Atmospheric Circulation: Our atmosphere is a understandable through examination of its major components and interactions. Of course understanding the finer points means understanding the heat energy transfers from outside and within our atmosphere. That means energy from the sun and also how land and oceans transfer heat, which then affects how our atmospheric phenomena act with in the Earth system.
The Arctic/Polar Amplification Effect is mainly caused by a combination of a few things. The chief components include the magnitude of change regarding ice extent and snow cover loss allows for a more dramatic change in climate architecture of the polar region. This also relates to the amount of land in the northern hemisphere verses the southern hemisphere.
The AMO is an ongoing series of long-duration changes in the sea surface temperature of the North Atlantic Ocean, with cool and warm phases that may last for 20-40 years at a time and a difference of about 1°F between extremes. These changes are natural and have been occurring for at least the last 1,000 years. Source: http://www.aoml.noaa.gov/phod/amo_faq.php
Understanding Atmospheric Composition is both simple and handy in understanding how mankind can influence climate. Many people think the atmosphere is just too big for humans to influence? It sounds like a reasonable statement, until you realize that you don't need to change the whole atmosphere to change climate... you just need to change a little bit of it.
Climate attribution literally has to do with what causes something, or "to explain by indicating a cause". With regard to climate and weather it is important to understand the differences between what attribution can be assigned to climate and/or weather events at a given moment, or over a span of time. The longer the span of time, the more the attribution moves away from weather and towards climate, and vice versa.
GCM's (General Circulation Models) or sometimes mistakenly referred to as Global Climate Model, Typically refers to a three-dimensional model of the global atmosphere used in climate modeling (often erroneously called “Global Climate Model”). This term often requires additional qualification (e.g., as to whether or not the atmosphere is fully coupled to an ocean as in AOGCM, which stands for Atmosphere-Ocean General Circulation Model.
Climate Feedbacks: An interaction mechanism between processes in the climate system is called a climate feedback, when the result of an initial process triggers changes in a second process that in turn influences the initial one. A positive feedback intensifies the original process, and a negative feedback reduces it.
Climate forcing has to do with the amount of energy we receive from the sun, and the amount of energy we radiate back into space. Variances in climate forcing are determined by physical influences on the atmosphere such as orbital and axial changes as well as the amount of greenhouse gas in our atmosphere.
The 1470 Year Climate Cycle - Often quoted as the 1500 year cycle is a popular red herring used by S. Fred Singer and Dennis Avery. It is also a real climate cycle known as Dansgaard-Oeschger (D-O) events. It is not a global climate warming or cooling however beyond it's own cycle and related feedbacks. It appears to be an interval event of heat exchange in the oceanic system.
How the Earth stays warm has to do with the total amount of energy we receive from the sun (around 1366.5 W/m2 when measured in space, and the amount that actually makes it to the surface of Earth is estimated to be around 342 W/m2 on average. Once the energy makes it to the surface, it changes from short wave radiation to longwave radiation which is heat energy. Clouds, dark and light surfaces and greenhouse gases generally regulate the amount of energy that is held within our climate system.
An interesting twist in the argument about what can be projected is the idea that we can only accept the empirical. Another way to state this might be reality vs. modeling. Climate models as we have pointed out are always wrong. It is important to understand the difference between the observations (reality) and the empirical models.
Galactic Cosmic Rays have been considered as a possible relevant cause in our current global warming event. Examinations of claims that galactic cosmic rays are responsible four our current global warming event have been assessed through peer review and peer response. The consensus remains that there is no significant correlation between galactic cosmic rays and climate change, especially in relation to our current warming event.
Greenhouse Gases (GHG's) are the gases are the various gases that block outgoing long-wave infrared from easily leaving our atmosphere. The Greenhouse Effect (GHE) is the physical mechanism of this blocking mechanism in our atmosphere that determine to a variant degree, how much heat we retain within the atmosphere.
The ice is melting in Greenland. The ice melt rate is also accelerating. What does this mean? That depends on your context in time, your geographic location, and ultimately, why it is happening?
The history of climate science goes back to the early 1900's. This section contains a chronological listing of relevant climate science discoveries and events related to anthropogenic global warming. The information here was compiled by Spencer Weart (see links for reference).
How do we know this global warming is human caused, or man made? Is global warming real, or a hoax? Consider the facts: the climate has left the natural cycle path; multiple lines of evidence and studies from different fields all point to the human fingerprint on current climate change; the convergence of these evidence lines include ice mass loss, pattern changes, ocean acidification, plant and species migration, isotopic signature of CO2, changes in atmospheric composition, and many others. The only identifiable cause is human influence and increased greenhouse gas emissions. Science has simply not found any other cause factor that can account for the amount of current increased radiative forcing and associated warming.
The International Panel on Climate Change
Most understand the Keeling curve as an upward trend of CO2 in the atmosphere as measured by the Mauna Loa measurements of Charles David Keeling. But there are two Keeling curves and they are related to each other in more than one way. While CO2 increases, it stands to reason that O2 will decrease (C + O2 = CO2). The two curves also have family ties.
Global warming is not only expected to cause a latitudinal shift of the jet-stream, it already has. There has been a measured poleward of the jet-stream in the past 30 years. This is an expected result of global warming.
The Maunder Minimum was a period of low sunspot activity (a quiet sun). This low activity was correlated with a cooling period that caused crops to fail and had many impacts on the human economy.
The Medieval Warm Period (MWP) occurred around one thousand years ago. This is known by examinations of ice core records and multiple proxy models from multiple interrelated disciplines.
Methane is a strong Greenhouse gas and human activity has increased methane in our atmosphere around 148% since the beginning of the industrial age. Some evidence indicates regional climate shift based on natural methane release, such as those that may be associated with the demise of the Anastasi or the Inca's. More research is needed on causal relationships. Evidence in the paleo record indicates that methane release concurrent with other contributing factors can have substantial impacts on the earth climate. It is estimated that a warmer world increases the risk of methane release
What are Milankovitch Cycles? Natural global warming, and cooling, is considered to be initiated by Milankovitch cycles. These orbital and axial variations influence the initiation of climate change in long-term natural cycles of 'ice ages' and 'warm periods' known as 'glacial' and 'interglacial' periods. The cycles appear to be range bound in the paleo record for the past 5 million years. Our current climate forcing shows we are outside of that natural cycle forcing range.
This section is dedicated to information about the natural cycle in relation to changes in the atmosphere and forcing levels.
Natural variation includes internal and external variability influences such as the solar Schwabe cycle, oceanic cycles, seasonal influences based on changes caused by the interaction of the various natural oscillations in the climate system. These variations combined influence regional climate and weather on periodic basis as well as influence weather event patterns.
The North Atlantic Oscillation (NAO) is a measure of the strength of the westerlies across the North Atlantic. Originally defined by Sir Gilbert Walker in 1932 as the difference in pressure between Ponta Delgada on the Azores and Stykkisholmur in Iceland.
ENSO stands for El Niño/ Southern Oscillation. The ENSO cycle refers to the coherent and sometimes very strong year-to-year variations in sea- surface temperatures, convective rainfall, surface air pressure, and atmospheric circulation that occur across the equatorial Pacific Ocean. El Niño and La Niña represent opposite extremes in the ENSO cycle.
The Southern Oscillation Index (SOI) is one measure of the large-scale fluctuations in air pressure occurring between the western and eastern tropical Pacific (i.e., the state of the Southern Oscillation) during El Niño and La Niña episodes. Traditionally, this index has been calculated based on the differences in air pressure anomaly between Tahiti and Darwin, Australia.
The Pacific Decadal Oscillation is a long-term fluctuation of the Pacific Ocean that waxes and wanes between cool and warm phases approximately every 5 to 20 years. In the cool phase, higher than normal sea-surface heights caused by warm water from a horseshoe pattern that connects the north, west and southern Pacific, with cool water in the middle. During most of the 1980s and 1990s, the Pacific was locked in the oscillation's warm phase, during which these warm and cool regions are reversed. http://www.jpl.nasa.gov/news/news.cfm?release=2008-066
Pacific / North American Pattern (PNA) – The Pacific/ North American teleconnection pattern (PNA) is one of the most prominent modes of low-frequency variability in the Northern Hemisphere extratropics. The positive phase of the PNA pattern features above-average heights in the vicinity of Hawaii and over the intermountain region of North America, and below-average heights located south of the Aleutian Islands and over the southeastern United States.
Greg Craven has done a very good job of outlining the basic science and risks analysis in a series of videos that he has produced in response to the concerns over the actual science as well as those skeptical of that science. From a risk perspective, he has done a wonderful job in the series. The science has only a few minor representations that are generally slightly out of context. This does not take away from the excellent risk analysis presentation of the arguments.
National and international security concerns regarding global warming.
Information about Solar Irradiance.
Global Temperature: NCAR/UCAR, NCDC, and NASA GISS Analysis: The current analysis uses surface air temperatures measurements from the following data sets: the unadjusted data of the Global Historical Climatology Network (Peterson and Vose, 1997 and 1998), United States Historical Climatology Network (USHCN) data, and SCAR (Scientific Committee on Antarctic Research) data from Antarctic stations. The basic analysis method is described by Hansen et al. (1999), with several modifications described by Hansen et al. (2001) also included. Modifications to the analysis since 2001 are described on the separate Updates to Analysis.
The context of thermal inertia in long-term is different than short-term
This section is dedicated to information about climate tipping points.
Weather intensities are driven by natural variations and overall climate forcing. Forcing agents vary such as surface reflectivity, greenhouse gases and natural variation in atmospheric and ocean cycles as well as longer term forcing agents such as the Milankovitch cycles that drive long term climate change. Even longer term forcing agents have to do with tectonic shifts over millions of years.
What is the difference between weather and climate? Weather is considered short-term variability, while climate is long-term trend based on multiple factors. These factors depend on context. In other words, one persons weather is another persons climate. Generally speaking, in the context of human caused global warming, climate is considered 30+ years of trend with attribution.
Paleoclimatology Records: The Paleo Temperature Record: From the World Data Center for Paleoclimatology: If anyone is not sure if there are enough measurements for us to have a good idea of what the past temperature and atmosphere was, the following list shows the types and disciplines from which paleo data is measured to model the past climate of earth.
Often when someone realizes that climate is an important issue and that human-kind is influencing the climate, the next obvious question arises. What can we do? Here are some simple steps and considerations that we can all do to help.
One of the important questions concerns what we don't know. This section is dedicated to putting what we don't know into perspective with what we know in order to understand what it means.
The Ralph Keeling Curve