Climate TimeLine Fact Sheet

• What is the Climate TimeLine?
• What is the difference between Weather and Climate?
• Graphic Overview of Climate System Dynamics
• Overview of Climate Processes
• -Big Picture- Solar Energy
• -The Greenhouse Planet
• -Climate & Water Balance
• -Time Scales of Climate Change
• How is Climate related to the Hydrologic Cycle?
• What is variability
• How do we measure past climate?
• What is paleoclimatology?
• What do different paleo proxies tell us about climate variability?
• Temporal Scope and Potential Information from Paleoclimatic Proxies
• What factors are key to measuring climate change?
• What is climate forcing and how does it relate to climatic variability and change?
• What is time and how is it measured?
  

What is the Climate TimeLine?
Designed as an online tool allowing users to examine climate change and variability at different time scales, the Climate TimeLine has been developed through a CIRES Innovative Research Grant through the NOAA Paleoclimatology Program which is part of the National Climatic Data Center. The work has been conducted with the assistance of the National Geophysical Data Center (NGDC), located at NOAA's Boulder Laboratory.

The Climate TimeLine has been selected by the National Science Teachers Association's SciLinks Program for excellence in science education. In particular, the Climate TimeLine helps in the following science education standard:

Subject: Earth Science
Topic: Energy in the earth system
Concept: Global climate is determined by energy transfer from the sun at and near the earth's surface. (Grades 9-12) The SciLinks program has expanded this general standard to include explanations for the occurrence of ice ages include changes in the Earth's orbit, volcanic eruptions, changes in the sun's energy output, plate tectonics, and continental drift.

Beginning with daily diurnal cycles and climate and weather forecasts for the near-term, the Climate Time Line uses the exponential powers of ten to frame time periods from annual to 100,000 year scales, with a brief overview of natural history and climate for even older time frames. Each time period has an overview and sections on climate science, climate history and resources, including online links and inquiry questions for further exploration. For more information contact Mark McCaffrey or Dan Kowal.

What is the difference between Weather and Climate?

Weather is the state of atmosphere-ocean-land conditions (hot/cold, wet/dry, calm/stormy, sunny/cloudy) that exist over relatively short periods like hours or days. Weather includes the passing of a thunderstorm, hurricane, or blizzard, a persistent heatwave, a cold snap, a drought. Weather variability and extreme events may respond unpredictably in response to climate change.

Climate is weather patterns over a month, a season, a decade, a century from now or in past time periods. More technically climate is defined as the weather conditions resulting from the mean state of the atmosphere-ocean-land system, often described in terms of "climate normals" or average weather conditions.

Or, to put it another way, weather is what determines what clothes we wear to go outdoors on a given day. Climate is what determines what crops we plant and when we we plant and harvest them.

How is Climate related to the Hydrologic Cycle?

The hydrologic cycle has been described as the Earth's thermostat, keeping the planet's climate from either becoming so cold that all water freezes (as on Mars) or so hot that all water is vaporized (as on Venus.) Water vapor is the primary greenhouse gas in the atmosphere. Were it not for an active greenhouse effect, the Earth's temperature would be some 32 degrees Celsius (60F) colder than it is today, and most water would likely be frozen. Climate forces, including external (such as the tilt of the Earth's axis) and internal (ocean dynamics) can impact the dynamics of the hydrologic cycle.

Images from NOAA and USGS