Climate Matters • November 25, 2020

New Presentation: Our Changing Climate

Key concepts:.

Climate Central unveils Our Changing Climate —an informative and customizable climate change presentation that meteorologists, journalists, and others can use for educational outreach and/or a personal Climate 101 tool.

The presentation follows a ”Simple, Serious, Solvable” framework, inspired by climate scientist Scott Denning. This allows the presenter to comfortably explain, and the viewers to easily understand, the causes (Simple), impacts (Serious), and solutions (Solvable) of climate change. 

Our Changing Climate is a revamped version of our 2016 climate presentation, and includes the following updates and features:

Up-to-date graphics and topics

Local data and graphics

Fully editable slides (add, remove, customize)

Presenter notes, background information, and references for each slide

Supplementary and bonus slides

Download Outline (PDF, 110KB)

Download Full Presentation (PPT, 148MB)

Updated: April 2021

Climate Central is presenting a new outreach and education resource for meteorologists, journalists, and others—a climate change presentation, Our Changing Climate . This 55-slide presentation is a guide through the basics of climate change, outlining its causes, impacts, and solutions. This climate change overview is unique because it includes an array of local graphics from our ever-expanding media library. By providing these local angles, the presenter can demonstrate that climate change is not only happening at a global-scale, but in our backyards.

This presentation was designed to support your climate change storytelling, but can also double as a great Climate 101 tool for journalists or educators who want to understand climate change better. Every slide contains main points along with background information, so people that are interested can learn at their own pace or utilize graphics for their own content. 

In addition to those features, it follows the “Simple, Serious, Solvable” framework inspired by Scott Denning, a climate scientist and professor of atmospheric science at Colorado State University (and a good friend of the program). These three S’s help create the presentation storyline and outline the causes (Simple), impacts (Serious), and solutions (Solvable) of climate change. 

Simple. It is simple—burning fossil fuels is heating up the Earth. This section outlines the well-understood science that goes back to the 1800s, presenting local and global evidence that our climate is warming due to human activities.

Serious. More extreme weather, rising sea levels, and increased health and economic risks—the consequences of climate change. In this section, well, we get serious. Climate change impacts are already being felt around the world, and they will continue to intensify until we cut greenhouse gas emissions. 

Solvable. With such a daunting crisis like climate change, it is easy to get wrapped up in the negative impacts. This section explains how we can curb climate change and lists the main pathways and solutions to achieving this goal. 

With the rollout of our new climate change presentation, we at Climate Central would value any feedback on this presentation. Feel free to reach out to us about how the presentation worked for you, how your audience reacted, or any ideas or topics you would like to see included. 

ACKNOWLEDGMENTS & SPECIAL THANKS

Climate Central would like to acknowledge Paul Gross at WDIV-TV in Detroit and the AMS Station Science Committee for the original version of the climate presentation, Climate Change Outreach Presentation , that was created in 2016. We would also like to give special thanks to Scott Denning, professor of atmospheric science at Colorado State University and a member of our NSF advisory board, for allowing us to use this “Simple, Serious, Solvable” framework in this presentation resource.

SUPPORTING MULTIMEDIA

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The Greenhouse Effect, Greenhouse gases

Global warming and climate change

The Greenhouse effect

  • A natural process in our atmosphere
  • Makes the climate hospitable = good thing
  • Sun radiates electromagnetic energy Ultraviolet light passes through atmosphere
  • Water/earth absorb energy, re-radiated out as infrared energy – longer wavelengths
  • Greenhouse gases in atmosphere trap IR energy
  • Visible light = 43% of sun’s emitted energy
  • Shorter wavelengths have more energy
  • GHG absorb and re-radiate IR energy in all directions, warming the planet

Greenhouse effect cont..

  • If not for this process, the earth would be much cooler than it is now
  • Land cover strongly affects how much energy is absorbed
  • Ice reflects most energy = very small GHE
  • Dark surface absorb = very large GHE
  • Albedo – The percent of energy reflected

Greenhouse Gases

  • Four primary greenhouse gases:
  • Carbon dioxide, water vapor , methane , nitrous oxide (others as well - Halocarbons)
  • Molecules composed of 3 or more atoms
  • Loosely bonded, and can vibrate when exposed to IR energy
  • Oxygen and Hydrogen – diatomic – bonds too strong to vibrate

Natural sources of GHG

  • Respiration – plants and animals
  • Natural flux between ocean and atmosphere
  • Natural leaks of methane from reservoirs and anaerobic bacterial decomposition
  • Forest fires

Anthropogenic sources – Carbon Dioxide

  • Primary GHG – abundance and rate of increase current rate is 416 ppm (Mauna Loa data)
  • Combustion of fossil fuels
  • Cement manufacturing
  • Clearing and burning of forests
  • Depletion of soils

Increase in Carbon Dioxide – fossil fuel combustion 2011-2012

  • From NOAA.gov
  • E. Asia, W. Europe, and NE America
  • Concentration is not equally distributed
  • Dispersed by global climate patterns

Keeling Curve

Anthropogenic sources - Methane

  • Drilling/transporting/using fossil fuels
  • Agriculture – especially rice
  • Ruminants – digestion and manure storage – CAFO’s

Methane - USA

Anthropogenic sources – Nitrous Oxide

  • 5% of US GHG emissions
  • Feedlots – CAFO’s
  • Chemical Manufacturing plants – Fertilizer, adipic acid – used for nylon and other fibers
  • Auto emissions
  • Over-application of Nitrogen Fertilizers

Source: IGPCC – 4 th assessment

Halocarbons

  • Best known as Ozone destroyers
  • -Chlorofluorocarbons – CFC’s
  • Largely been wiped out due to Ozone depletion – Montreal Protocol
  • Refrigerants and industrial solvents
  • Have been replaced with fluorinated gases

Fluorinated gases

  • Replaced CFC’s with a class of chemicals called fluorinated gases - GHG
  • Sulfur hexafluoride - SF 6
  • Hydrofluorocarbons - HFC’s
  • Perfluorocarbons - PFC’s
  • Nitrogen trifluoride - NF 3
  • Released through usage (propellants) leaks during manufacturing, and disposal

Carbon Emissions by country

Per capita Carbon emissions

Considerations for Greenhouse gases

  • Global Warming Potential (GWP): How effective are they at absorbing and re-radiating energy – relative to carbon dioxide
  • Residence time – How long do these gases remain in the atmosphere
  • Rate of increase in concentration

Not all Greenhouse Gases are created equal

Radiative Forcing

External Links for GHGs

EPA: Overview of major GHG emissions

NOAA: Global Monitoring Laboratory

NASA: Global Climate Change

Factors that contribute to natural climate variability

We need to understand these natural factors in order to determine whether or not the change we are currently observing is due to human activity or a reflection of natural climate cyclicity

  • Milankovitch cycles
  • Solar output

Natural Factors that Affect Climate

Eccentricity - The shape of the Earth’s orbit - 100,000 year cycle

Obliquity - The angle of the Earth’s axis - 41,000 year cycle

Precession - axial wobble - 25,771 year cycle

Deep sea sediments, ice cores, and others support MC driving glacial periods

Solar Output

Ocean Absorption

Ocean circulation

ENSO - El Nino Southern Oscillation

  • Trade winds interaction with the pacific ocean between the Americas and Asia
  • El Nino - weaker winds - warmer waters migrate towards the Americas
  • La Nina - stronger winds - warmer water migrate towards Asia, leading to cooler waters upwelling
  • Short Video here

Global Warming….

  • Current average global temperatures have increased by 1.01 degrees C (1.8 degrees F) since pre-industrial times.
  • All science studies show this change is anthropogenic
  • Data analysis of natural vs. Anthropogenic effects of global warming

So what is Global Warming?!!

  • Definition: a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, chlorofluorocarbons, and other pollutants.
  • Not consistent everywhere

Global temperature trend� Note that these are surface temperatures and mostly overland. The temperature in upper levels may be different, even reversed.

Understanding past climates

  • Science has good evidence the climate has changed many times in the past
  • What is the EVIDENCE of this past change?
  • What are the CAUSES of this historic change?
  • How do we know the current change isn’t a NATURAL result of these factors?

Proxy Indicators

  • Proxy indicatiors are indirect evidence of the distant past.
  • Validity of proxy indicators is achieved by comparing many different indicators and getting similar results.
  • Proxy indicators include:
  • Ice cores- oxygen isotopes (temperature) and CO 2 concentration
  • Coral reefs and shelled organisms like clams
  • Sediments - deep ocean/lake - pollen grains
  • Cave formation
  • Pack rat middins
  • Glacial deposits
  • There are others too.

Ice Core Bubbles VIDEO

Using Oxygen Isotopes

  • Isotope - same number of PROTONS, different number of NEUTRONS
  • Oxygen - 8 protons
  • “Heavy Oxygen” - Oxygen 18
  • “Light Oxygen” - Oxygen 16
  • Ratio of these two is indicative of past climates

Oxygen Isotope Data

CO 2 vs. Temperature

Impacts of Warming Climate - Melting Ice caps and glaciers�

  • Arctic summers could be ice free by 2040
  • Melting at 9% per year, thickness decreased by 40% since 1960’s
  • Loss of habitat for polar bears, seals, walrus’s, and whales, krill
  • Loss of plants
  • Threats to native peoples
  • Increases absorption of thermal radiation
  • Loss of drinking water

Arctic sea ice

Of course the physical environmental change will lead to changes in the biosphere – including our society.

Ice shelves of the South Pole have partly separated and are collapsing. (NASA)

Receding high mountain glaciers

Melting ice and rising sea level

Impacts of Warming Climate - Increased temperature

  • hotter summers
  • More money for energy
  • More deaths due to heat waves
  • Shifting agricultural regions – increased seasons
  • More evaporation – less water - Drier crops
  • More frequent and intense forest fires
  • More extreme precipitation events too
  • Warmer winters –
  • Spread of pests – agricultural and disease vector
  • Spread of invasive plant and animal species
  • Extinction – coral reefs, plant and animal species

NASA Climate Change

Impacts of Warming Climate – Warmer oceans

  • Warmer surface temperatures will lead to stronger storms
  • Flooding, habitat destruction, erosion, salinization
  • Coral bleaching – 25% of ocean species live in coral reefs
  • Decreased ability for oceans to dissolve gases
  • Oxygen, carbon dioxide
  • Will affect ocean currents and weather patterns
  • Rising sea levels (thermal expansion)
  • Sea level will rise (thermal expansion, melting) – 8 inch rise since 1880, 1’-4’ by 2100

As Greenland melts and storms increase the Gulf stream slows. Article link here

Coral bleaching - increasing ocean temperatures

Impacts of Warming Climate – Economic and societal

  • Disproportionately affect lower socio-economic class
  • Spend more money on energy
  • Loss of productivity – plants and animals
  • Property damage
  • Flooding of low areas – entire countries could vanish
  • Mass migration – cause societal stress – increase in crime
  • Security threats, instability
  • Hope for new inventions/innovations/economic boom

Climate Change

  • Definition: Climate change is any substantial change in Earth’s climate that lasts for an extended period of time.
  • The climate has changed many times in the past – 7 recorded ice ages
  • Perhaps the most damaging change is occurring now..

Feedback Effect

  • The climate system is very complicated.
  • A change in one component of the system may cause changes in other components.
  • positive feedback - Sometimes the changes in other components enhance the initial change, then we say that these changes have to the system.
  • negative feedback - If the changes result in the reduction of the original change, then they have
  • Both positive and negative feedback processes may exist in the climate system.
  • Take all such possible complicated effects into account. A good climate model would have treated all of them realistically.

An example of positive feedback

  • When the climate becomes warmer (either due to the increase of CO 2 in the atmosphere or other unknown mechanisms), the ocean may also become warmer. A warmer ocean has lower solubility of CO 2 and hence will release more CO 2 into the atmosphere. This may cause the climate to become even warmer than before. Thus the dependence of solubility of CO 2 on temperature has a positive feedback on the climate system.

An example of negative feedback

  • Consider a clear region over the ocean. Since there is no cloud, the sun shines on the ocean surface, causing it to warm up. This makes this part of the ocean warmer than other parts and the air over it tends to rise (causing convection). As we have learned before, rising air expands and cools, causing clouds to form. The formation of clouds will block out the sun and the solar heating of the ocean surface will cease. The surface will start to cool down. Thus the cloud formation due to surface heating and convection is a negative feedback to the climate system.

Effects of Climate Change

  • Shifting precipitation patterns
  • Flooding, erosion, drought
  • Mass extinctions – as much as 25% of existing species could be headed toward extinction by 2050
  • Less fresh water available in some areas
  • Spread of disease vectors – more heat and less biodiversity
  • Increased pollution