NOAA-ISET

Frequently Asked Questions

  1. How do I visit the NOAA ISET Cooperative Science Center?
  2. What is the Earth system?
  3. What is the “greenhouse effect”?
  4. Is the “greenhouse effect” the same as “global warming”?
  5. What will be the effect of continued increase of greenhouse gases?
  6. Do scientists disagree about the greenhouse effect and global warming?
  7. If damaging effects are in the future, what’s the urgency?
  8. What are the key uncertainties in seasonal to interannual predictions and long-term projections of water cycle variables, and what improvements are needed in global and regional models to reduce these uncertainties?
  9. To what extent can uncertainties in model projections due to climate system feedbacks be reduced?
  10. How can information on climate variability and change be most efficiently developed, integrated with non-climatic knowledge, and communicated in order to best serve societal needs?
  11. What are the environmental, social, economic, and human health consequences of current and potential land-use and land-cover change over the next 5 to 50 years?

  1. How do I visit the NOAA ISET Cooperative Science Center?
    See NC A&T Campus (http://www.ncat.edu/campus/) for maps and directions.
  2. What is the Earth system?
    The Earth as a whole is an integrated system of oceanic, atmospheric and ecological interactions. Understanding these integrated processes is necessary to assess issues related to climate change, ozone depletion, air quality and weather prediction.
  3. What is the “greenhouse effect”?
    When sunlight hits the earth, the earth is warmed and radiates some of that heat back towards space. Certain gases in the atmosphere (known as “greenhouse gases”) can absorb some of that radiation, preventing it from escaping. The earth retains more heat from the sun than it would in the absence of these gases, making the earth about 35°C warmer than it would be otherwise. Without this greenhouse effect, the earth would likely be a giant ice ball. Life as we know it would not exist.

    The planet Venus (earth's "sister planet" ) provides a striking example of the impact of the greenhouse effect.  It has a surface temperature of 750° K, hot enough to melt lead.  The surface temperature is twice that of Mercury, even though Mercury is much closer to the sun.  This is because  Venus has a "runaway greenhouse effect" due to its dense atmosphere of 96% CO2 . This effect is estimated to raise the surface temperature of Venus 400° K.

  4. Is the “greenhouse effect” the same as “global warming”?
    No. As the amount of greenhouse gases (such as CO2) increases so does their warming effect. Increasing greenhouse gases in the atmosphere can lead to global warming.

  5. What will be the effect of continued increase of greenhouse gases?
    No one knows for sure but likely effects include sea-level rise and changes in weather patterns.  Greenhouse gases, especially CO2 , have been rising for over a hundred years due to industrialization (especially burning fossil fuels , http://www.fe.doe.gov/education/energylessons/ ) and deforestation .  

    Many scientists conclude that this increased greenhouse effect is already causing global warming.  There appears to be a link between the increase in greenhouse gases and a gradual (1° F) increase in average global temperature during the past century, especially in polar regions.  Sea ice in polar regions appears to be shrinking.  Less ice may lead to greater absorption of solar radiation. 

    As the earth begins to warm another greenhouse gas, methane or "natural gas" , which is trapped in the oceans and boggy soil, may be released, further increasing the greenhouse effect and accelerating global warming.  The earth has undergone many cycles of global warming and cooling over millions of years, causing significant changes to life on the planet.  But the exact nature of these changes is unpredictable.  For example, one surprising possible effect of global warming may be a new ice age !

    To learn more about past warming/cooling cycles click here .
  6. Do scientists disagree about the greenhouse effect and global warming?
    No!  

    Scientists seldom agree 100% on anything , but the vast majority of reputable scientists agree that increasing levels of certain atmospheric gases (like CO 2 ) contribute to global warming.  There is essentially no disagreement that growing use of fossil fuels on the current upward trend will lead to increased global warming.  If there is disagreement, it is regarding the impact and timing of consequences due to this warming.  Some models predict catastrophic effects like rising sea levels within our lifetimes.  (Indeed, we can already observe substantially increased melting of polar ice.)   Some predict stronger hurricanes immediately.  (That additional heat must go somewhere, somehow.)  Others say damaging effects are farther in the future. 

    To learn more about global warming and hurricanes click here .
  7. If damaging effects are in the future, what’s the urgency?
    Many scientific models show what is called a "tipping point in global warming".   (The "tipping point" is the point beyond which our attempt to avoid catastrophe will be ineffective.)  When average global temperatures consistently rise to a certain level global warming may spiral out of control.  For example, when more polar ice melts, earth's surface becomes less reflective, on average, and more solar radiation will be absorbed.  This raises temperatures more, causing more polar ice to melt, etc.  Permafrost melts, releasing billions of tons of greenhouse gases into the atmosphere accelerating global warming. 

    To learn more about the effect of global warming on arctic regions click here .

    Most scientists believe that we have not yet reached that tipping point.  However, it may arrive in the not-too-distant future. 

  8. What are the key uncertainties in seasonal to interannual predictions and long-term projections of water cycle variables, and what improvements are needed in global and regional models to reduce these uncertainties?
    Seasonal to interannual predictability is a function of local and remote influences involving various ocean and land processes. Enhanced predictability can result from persistence of specific phenomena or slowly varying boundary conditions (soil moisture/groundwater, snow/ice, vegetation/land cover, and ocean and land surface temperatures) that persist over periods of weeks, months, or even years. More accurate initial surface fields for prediction models produced by recently developed land data assimilation systems provide a basis for reducing prediction errors. Cloud and precipitation feedbacks and the interactions of the lower boundary layer (lower 500 meters of the atmosphere) with land and ocean surface conditions also are not well understood.
  9. To what extent can uncertainties in model projections due to climate system feedbacks be reduced?
    Climate system feedbacks, such as from clouds, water vapor, atmospheric convection, ocean circulation produce large uncertainties in climate change projections by modulating the direct response to radiative perturbations that result from changing greenhouse gas concentrations, solar variability, or land-cover changes. Important feedbacks include relatively fast processes on time scales of minutes to months, e.g., clouds and turbulent ocean mixing. Such rapid processes also affect models used for seasonal-to-interannual climate predictions, which can be used as effective test beds for research in this area.
  10. How can information on climate variability and change be most efficiently developed, integrated with non-climatic knowledge, and communicated in order to best serve societal needs?
    Research in this area focuses on making climate knowledge more useful and responsive to the needs of decisionmakers, policymakers, and the public. Climate information, when integrated together with knowledge of non-climatic factors, can reduce costs and risks related to climate variability and change while increasing management and decisionmaking opportunities across a broad range of sectors, from local and regional to global scales.
  11. What are the environmental, social, economic, and human health consequences of current and potential land-use and land-cover change over the next 5 to 50 years?
    There is clear evidence that changing land use and land cover has significant impacts on local environmental conditions and economic and social welfare. For example, the water cycle depends heavily on vegetation, surface characteristics, soil properties, and water resources development by humans (e.g., dam construction, irrigation, channeling, and drainage of wetlands) which in turn affects water availability and quality. Land-use and land-cover change, climate variability and change, soil degradation, and other environmental changes all interact to affect natural resources through their effects on ecosystem structure and functioning. In turn, ecological systems may respond unexpectedly when exposed to two or more perturbations.