Information largely from NASA website (http://climate.nasa.gov/evidence) with interpretive slides pulled from Wikipedia and other websites.

1. DeLapa | Consulting
Climate Change -
The Earth Is Warming
How and What We Know

2. DeLapa | Consulting
The Logic
1. Concentrations of greenhouse gases (CO2, methane, others) are
increasing in the atmosphere.
2. Greenhouse gases trap heat (i.e., Greenhouse Effect).
3. Scientific evidence (data) of atmospheric and oceanic warming is
overwhelming. Over the past 30 years the data has only gotten
stronger.
4. 97%+ of climate scientists agree that human activities, principally
the burning of hydrocarbons, are causing the earth to warm and
the climate to change quickly and dramatically.
5. Every reputable scientific association accepts this as fact as well.

3. DeLapa | Consulting
Atmospheric CO2 Over the Past
400,000 Years
This graph, based on the comparison of atmospheric samples contained in ice
cores and more recent direct measurements, provides evidence that
atmospheric CO2 has increased since the Industrial Revolution. (Source: NOAA)

4. DeLapa | Consulting
Atmospheric CO2
Over the Past 60 Years
The Keeling Curve is a graph which plots the ongoing change in concentration of carbon
dioxide in Earth's atmosphere since 1958. It is based on continuous measurements taken at
the Mauna Loa Observatory in Hawaii that began under the supervision of Charles David
Keeling. Keeling's measurements showed the first significant evidence of rapidly increasing
carbon dioxide levels in the atmosphere. Source: Wikipedia

5. DeLapa | Consulting
The Greenhouse Effect – Simple

6. DeLapa | Consulting
The Greenhouse Effect – Less Simple
The increase in atmospheric CO2
and other greenhouse gases has
increased the amount of infrared
radiation absorbed and re-emitted
by these molecules in the
atmosphere. The Earth receives
energy from the Sun in the form of
visible light and ultraviolet
radiation, which is then re-radiated
away from the surface as thermal
radiation in infrared wavelengths.
Some of this thermal radiation is
then absorbed by greenhouse gases
in the atmosphere and re-emitted
in all directions, some back
downwards, increasing the amount
of energy bombarding the Earth's
surface. This increase in downward
infrared radiation has been
observed through spectroscopy,
which measures changes in the
electromagnetic spectrum. –
Source: Skeptical Science

7. DeLapa | Consulting
Rising Global Temperatures
Global mean land-ocean
temperature change from 1880–
2012, relative to the 1951–1980
mean. The black line is the annual
mean and the red line is the 5-year
running mean. The green bars show
uncertainty estimates. Source: NASA
GISS
All three major global surface
temperature reconstructions show
that Earth has warmed since 1880.
Most of this warming has occurred
since the 1970s, with the 20
warmest years having occurred since
1981 and with all 10 of the warmest
years occurring in the past 12 years.
Even though the 2000s witnessed a
solar output decline resulting in an
unusually deep solar minimum in
2007-2009, surface temperatures
continue to increase. Source: NASA

8. DeLapa | Consulting
Warming Oceans
The oceans have absorbed much
of this increased heat, with the
top 700 meters (about 2,300 feet)
of ocean showing warming of
0.302 degrees Fahrenheit since
1969 Source: NASA

9. DeLapa | Consulting
Shrinking Ice Sheets - Global
Global glacial mass balance in the
last fifty years, reported to the
WGMS and NSIDC. The increasing
downward trend in the late 1980s
is symptomatic of the increased
rate and number of retreating
glaciers. Source: Wikipedia

10. DeLapa | Consulting
Shrinking Ice Sheets - Greenland
Satellites use gravity data to
measure the total mass balance
and have found the ice sheet is
losing ice mass at an accelerating
rate (Velicogna 2009).
The Greenland and Antarctic ice
sheets have decreased in mass.
Data from NASA's Gravity
Recovery and Climate Experiment
show Greenland lost 150 to 250
cubic kilometers (36 to 60 cubic
miles) of ice per year between
2002 and 2006, while Antarctica
lost about 152 cubic kilometers
(36 cubic miles) of ice between
2002 and 2005. Source: NASA

11. DeLapa | Consulting
Declining Arctic Sea Ice
September ice extent from 1979
to 2009 shows a continued
decline. The September rate of
sea ice decline since 1979 has
now increased to 11.2 percent
per decade. Sea Ice Index data.
—Credit: National Snow and Ice
Data Center
Both the extent and thickness of
Arctic sea ice has declined rapidly
over the last several decades.
Source: NASA

12. DeLapa | Consulting
Glacial Retreat
Global glacial mass balance in the last fifty
years, reported to the WGMS and NSIDC. The
increasing downward trend in the late 1980s
is symptomatic of the increased rate and
number of retreating glaciers. Source:
Wikipedia

13. DeLapa | Consulting
Sea Level Rise
Global sea level rose
about 17 centimeters
(6.7 inches) in the last
century. The rate in the
last decade, however, is
nearly double that of
the last century. Source:
NOAA

14. DeLapa | Consulting
Increase in Extreme Events
The number of record high
temperature events in the
United States has been
increasing, while the
number of record low
temperature events has
been decreasing, since
1950. The U.S. has also
witnessed increasing
numbers of intense
rainfall events. Source:
NASA
The ratio of record daily
high temperatures to
record daily lows observed
at about 1,800 weather
stations in the 48
contiguous United States
from January 1950
through September 2009.
The authors of a recent study, Rahmstorf & Coumou (2011), sought to find out is
how much of these extreme events can we put down to the slowly evolving
change in climate, and how much is due to random variations in weather. They
developed a statistical approach to evaluate record-breaking events. They
found that long-term warming increased the odds of record warm events in
global temperature, and when applied to the 2010 monster summer heatwave in
Moscow, Russia, they calculated an 80% probability the record-breaking
heatwave would not have happened without climate warming.

15. DeLapa | Consulting
Ocean Acidification
Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30
percent. This increase is the result of humans emitting more carbon dioxide into the atmosphere and hence more
being absorbed into the oceans. The amount of carbon dioxide absorbed by the upper layer of the oceans is
increasing by about 2 billion tons per year. Source: NASA

16. DeLapa | Consulting
Scientific Consensus
Consensus: 99.84% of Peer-Reviewed Articles Support
the Idea of Global Warming. DeSmogBlog

17. DeLapa | Consulting
Scientific Consensus
Data from 2010 (with signficantly more scientific data since then).

18. DeLapa | Consulting
Scientific Consensus
American Association
for the Advancement
of Science
"The scientific
evidence is clear:
global climate change
caused by human
activities is occurring
now, and it is a
growing threat to
society." (2006)
American Chemical
Society
"Comprehensive
scientific assessments
of our current and
potential future
climates clearly
indicate that climate
change is real, largely
attributable to
emissions from
human activities, and
potentially a very
serious problem."
(2004)
American Geophysical
Union
"Human‐induced
climate change
requires urgent
action. Humanity is
the major influence
on the global climate
change observed over
the past 50 years.
Rapid societal
responses can
significantly lessen
negative outcomes."
(Adopted 2003,
revised and
reaffirmed 2007,
2012, 2013)
American
Meteorological Society
"It is clear from
extensive scientific
evidence that the
dominant cause of the
rapid change in climate
of the past half century
is human-induced
increases in the amount
of atmospheric
greenhouse gases,
including carbon dioxide
(CO2),
chlorofluorocarbons,
methane, and nitrous
oxide." (2012)