For comparison: 217 miles is also about the same distance (as the crow flies) between Syracuse, N.Y. and Philadelphia, Pa.; Detroit, Mich. and Cincinnati, Ohio; or Los Angeles and Monterey, Calif.

Seasons: Spring, Summer, Fall

Sources: Jones, SJ et al. “Rising environmental temperatures and biogeography: poleward range contraction of the blue mussel, Mytilus edulis L., in the western Atlantic.” Journal of Biogeography. Published Online 19 August 2010, DOI : 10.1111/j.1365-2699.2010.02386.x and Science Daily. “Too Hot to Handle: Impacts of Climate Change on Mussels.” 19 August 2010. Accessed Online 25 August 2010 <http://www.sciencedaily.com/releases/2010/08/100816110404.htm>

For comparison: U.S. wheat production is about 2.16 billion bushels per year, for a total weight (assuming 13 percent moisture content) of 58,800,000,000,000 grams (130 billion pounds). This is about 1/2092nd of the total amount of carbon that is taken up by land plants each year. For further comparison, 123 petagrams is about the same weight as a 1.3 million Nimitz Class aircraft carriers.

Seasons: Winter, Spring, Summer, Fall

Sources: Beer, C et al. “Terrestrial Gross Carbon Dioxide Uptake: Global Distribution and Covariation with Climate.” Science 329 (2010): 834-838 and Reich, PB. “The Carbon Dioxide Exchange.” Science 329 (2010): 774-775.

At high-latitude locations, such as Alaska, Siberia and the Yukon Territory, lands dominated by grasses tend to be cooler than lands where shrubs and trees grow. Grasses are better able to withstand the long, harsh winters and high winds that characterize the far North. Grasses also reflect more sunlight than darker trees and shrubs meaning that once established, trees and shrubs actually make the surrounding environment warmer than it otherwise would have been by absorbing more sunlight. The warming makes more tree and shrub growth and further establishment of similar species more likely. This dynamic is known as a positive feedback cycle, where initial perturbations create conditions making more similar perturbations possible. As Earth came out of the last ice age (between 14,000 and 10,000 years ago) shrubs and trees moved into grasslands. This movement accelerated with the disappearance of large mammals, such as the Wooly Mammoth, from the high northern latitudes. The closest relatives of the mammoths – modern day elephants – consume almost everything vegetated that they can find. In Africa, a single elephant can devour or uproot 1,500 trees per year. This herbivory reduces the amount of trees and shrubs that can grow, keeping the land in a grassland or savannah state. In Alaska and the Yukon, the extinction of the Wooly Mammoth corresponded to the arrival of humans, who are known to have actively hunted mammoths. During a 1,000 year window around 13,800 years ago, trees and shrubs rapidly expanded, the Wooly Mammoth disappeared, humans arrived and the region warmed by 0.36 degrees Fahrenheit, with some locations warming by up to 1.6 degrees.

Seasons: Winter, Spring, Summer, Fall

Source: Doughty, CE et al. “Biophysical feedbacks between the Pleistocede megafauna extinction and climate: The first human-induced global warming?” Geophysical Research Letters 37 (2010): L15703.

Trivia Question: As the oceans absorb more carbon dioxide, they become…

a. more basic (higher pH).
b. more acidic (lower pH).
c. richer in nutrients.
d. warmer.

The correct answer is b. As oceans take CO2 out of the atmosphere, the waters become more acidic. More acidic waters mean there are less carbonate molecules available to organisms that use calcium carbonate to build their bodies, such as coral, oysters and many of the tiny plankton that are at the base of the food chain. One indicator of how this acidification has affected ocean life is the thickness of foraminiferan shells, which are a type of plankton. Samples from the Southern Ocean around Antarctica indicate that foramineferan shells, which are harder to make when there are fewer carbonate molecules, are now one-third thinner than they were in pre-industrial times.

Seasons: Winter, Spring, Summer, Fall

Sources: Hoegh-Guldberg et al. “Coral Reefs Under Rapid Climate Change and Ocean Acidification.” Science 318 (2007): 1737 and “Oceans Becoming More Acidic, Potentially Threatening Marine Life.” Science Daily 23 February 2009. Accessed Online 25 February 2009 <http://www.sciencedaily.com/releases/2009/02/090223091752.htm> and Moy, AD et al. “Reduced calcification in modern Southern Ocean planktonic foraminifera.” Nature Geoscience 2 (2009): doi:10.1038/ngeo460.

Trivia Question: How have marmots responded to this temperature rise and decrease in hibernation period?

a. They have become larger.
b. They have become smaller.
c. Their population has declined.
d. Their population has grown.
e. a and d.

The correct answer is e. Marmots now have more time to be active, eat and reproduce. As a result, today there are more marmots in the Colorado Rockies and they are bigger than they were several decades ago. Most of the population and size trends have occurred since 2000. There are now three times more marmots living in Colorado’s Upper East River Valley and juvenile marmots are now growing at a rate of 0.7 pounds per year faster than in 2000.

Please visit http://www.earthgauge.net/climate-facts-image-library#7 to download an image of a yellow-bellied marmot in Rocky Mountain National Park. The image is in the public domain.

Seasons: Spring, Summer

Sources: Martens, Chad. “Are Alpine Species DisappearingThe Effects of Climate Change on Alpine Vertebrates in the Rocky Mountains.” Mountain Research Station, University of Colorado, Boulder. Spring 2005 and Ozgul, A et al. “Coupled dynamics of body mass and population growth in response to environmental change.” Nature 466 (2010): 482-483.

For Comparison: The amount of chlorophyll in one cubic meter of sea water, 0.56 milligrams, is about the same mass as 10 grains of salt.

Seasons: Winter, Spring, Summer, Fall

Sources: Boyce, DG et al. “Global phytoplankton decline over teh past century.” Nature 466(2010): 591-596 and Science Daily “Marine Phytoplankton Declining: Striking Global Changes at the Base of the Marine Food Web Linked to Rising Ocean Temperatures.” 28 July 2010. Accessed Online 31 July 2010 <http://www.sciencedaily.com/releases/2010/07/100728131705.htm>

In Brief: Temperatures in local waterways are rising from a combination of factors.

Moving from Chicago to Baltimore, where the average temperature is about ten degrees Fahrenheit warmer, might take a little bit of adjustment but almost certainly wouldn’t be fatal for humans. Most fish and other aquatic species, however, would not survive an equivalent temperature change. Warmer water temperatures have contributed to the elimination of the Brook Trout from many streams in the eastern U.S. In the mid-Atlantic region, temperatures are becoming intolerable for some sensitive species like the Longnose dace and Cutlips minnow. Temperatures are beginning to enter the danger zone even for the relatively tough and tolerant Blacknose dace, the most common species in the region’s urban streams.

Annual mean water temperatures in the nation’s streams and rivers are increasing at an average rate of 0.016 and 0.139 degrees Fahrenheit per year, respectively. The Potomac River around our Nation’s capital is seven degrees warmer than it was in the 1920s and the Delaware River around Philadelphia is 4.5 degrees warmer that it was in 1965. Some likely factors behind the rising water temperatures include:

• A Warming Climate: Warming water temperatures are linked to the rise in surface temperatures that have occurred over the same period.
• Land Use Changes: Surfaces like concrete, asphalt and rooftops hold more heat more than vegetated ground, making runoff from urban areas warmer than runoff from rural or forested areas. These hard surfaces also prevent water from soaking into the ground, leading to sudden discharges of warm waters into streams and rivers. Urban runoff during a summertime thunderstorm can raise a stream’s temperature by 12 degrees in less than 30 minutes.
• Loss of Trees: Fewer trees on stream banks mean that streams receive more direct sunlight, raising their temperatures.
• Thermal Power Plants: Increased demand for electricity has led to the construction of more thermal power plants over the last century, and these power plants discharge hot water.
• Dams: Dams create large bodies of standing water, which absorb more energy than running water.

Seasons: Spring, Summer, Fall

(Source: Kaushal, SS et al. “Rising stream and river temperatures in the United States.” Frontiers in Ecology and the Environment 2010; 100323112848094 DOI: 10.1890/090037.)

Earth’s ecosystems changed rapidly 15,000 to 12,000 years ago and ecosystems in the western U.S. were no exception. The retreat of the region’s alpine glaciers during this period, which during glacial periods extended much farther into the valleys of the region’s mountain ranges than they do today, exposed new areas lands to plant colonization. In the Great Basin, a steady warming and drying trend evaporated the glacial age lakes that had dotted the landscape, leaving behind salt flats and the Great Salt Lake. The forests that had grown beside these lakes were replaced by deserts. Other transitions from one type of plant community to another were experienced across the rest of the region as species shifted in response to relatively gradual multi-millennial warming, as well as more rapid but short-lived transitions in response to sudden changes in ocean circulation. Even catastrophic floods periodically swept across the Columbia River Basin, destroying everything in their path. This was also the time when the first humans arrived in North America. During this period, the Pleistocene Megafauna, a group of species that included wooly mammoths, giant ground sloths, American lions and mastodons, went extinct. There has been much debate about whether these extinctions were caused by the arrival of humans with efficient hunting tactics or whether it was the climatic changes of the period that were chiefly responsible. An analysis of changes in small mammal populations, such as mice, gophers and shrews – species that would not have been actively hunted by humans – shows that more specialized species of small mammals were being out-competed and out-populated by more generalized species of mammals which were better adapted at adapting to rapidly changing landscapes. These small mammal population changes occurred before major declines in megafauna populations occurred. This suggests that while human hunting may have played a significant role in the extinctions of the Pleistocene Megafauna, shifts in populations that were already underway due to climate change was also an important factor.

Seasons: Winter, Spring, Summer, Fall

Source: Blois, JL et al. “Small mammal diversity loss in response to late-Pleistocene climatic change.” Nature 465 (2010): 771-774.

The Great Lakes region is an ecological “transition zone.” To the north lie boreal forests dominated by conifer trees. To the southwest lie oak savannas and prairies, and to the southeast lie deciduous oak-hickory woodlands. When the climate changes – average temperatures rise or rainfall in a given location changes – animals that are adapted to those conditions will often move to find the conditions for which they are best suited. Temperatures have warmed in the Great Lakes region over the past 30 to 40 years. Since 1985, surface temperatures on Lake Superior have been warming by an average of 1.2 degrees Fahrenheit per decade. Spring conditions are on average arriving earlier in the year and winters are milder, with average minimum temperatures up to 7.4 degrees Fahrenheit warmer than they were in the late 1960s.  As a result of these warming conditions, species better adapted to the conditions that were prevalent to the south of Michigan several decades ago – and are now normal in Michigan today – have moved into the state or have expanded their once marginal populations there. Woodland deer mice, for example, used to be dominant throughout the northern part of the Lower Peninsula, but have declined in number since white-footed mice moved in from the south. Flying squirrels, eastern chipmunks and opossums are now common or even abundant in parts of Michigan where they were largely unknown in the 1950s and 1960s.

Seasons: Winter, Spring, Summer, Fall

Source: Myers, P et al. “Climate-induced changes in the small mammal communities of the Northern Great Lakes Region.”  Global Change Biology 15 (2009): 1434-1454.

For Comparison: You could fit close to six Manhattans into 180 square miles; 180 square miles is also about the same size as Miami and Atlanta combined.

Seasons: Summer

Sources: Causey, Billy: “The History of Massive Coral Bleaching and other Perturbations in the Florida Keys.” In Chapter 6 of Coral Reefs in the U.S. and the Carribean. U.S. Coral Reef Information Service: National Oceanic and Atmospheric Administration and Eakin, Mark. Testimony before the House Committee on Natural Resources. U.S. House of Representatitves,17 April 2007 and Hoegh-Guldberg et al. “Coral Reefs Under Rapid Climate Change and Ocean Acidification.” Science 318 (2007): 1737 and United States. National Oceanic and Atmospheric Administration. Florida Keys National Marine Sanctuary: Visitor Information. 28 April 2008. Accessed Online: 18 September 2008 < http://floridakeys.noaa.gov/visitor_information/welcome.html> United States. National Oceanographic and Atmospheric Administration. NOAA Coral Reef Initiative. 1997. Accessed Online 18 September 2008 Wilkinson, C., Souter, D. (2008). Status of Caribbean coral reefs after bleaching and hurricanes in 2005. Global Coral Reef Monitoring Network and Reef and Rainforest Research Centre, Townsville, 152 p.

Atmospheric carbon dioxide (CO2) is a key plant nutrient, as carbon is the primary building block of all life on Earth. Other building blocks, however, are just as essential. Nitrogen, for example, is the mineral that plants require in the largest quantity. As atmospheric CO2 concentrations have risen from 280 parts per million to 390 over the last few centuries, scientists have started to ask questions about what this change  will do to plant growth. More CO2 appears to stimulate growth in some plants, notably parasitic climbing vines, poison ivy and weeds like Canadian Thistle. In other plants, which use different methods to convert carbon into plant matter, more CO2   can also affect a plant’s ability to absorb nitrate, the most common nitrogen compound found in agricultural soils.  Experiments done on wheat show that when this crop is grown under CO2 concentrations of  twice today’s levels, there is a 7.4 to 11 percent decline in the protein content of the wheat grains, making the grain less nutritious.

Seasons: Winter, Spring, Summer, Fall

Sources: Bloom, AJ et al. “Carbon Dioxide Enrichment Inhibits Nitrate Assimilation in Wheat and Arabidopsis.” Science 328 (2010): 899-903 and Phillips, OL et al. “Increasing dominance of large lianas in Amazonian forests.” Nature 418 (2002): 770-774 and “As CO2 Levels Rise, Plants—and Humans—Respond.” Agricultural Research Magazine. USDA Agricultural Research Service, Nov. & Dec. 2009. Web. Nov. 2009: Vol. 57, No. 10.

Earth’s plants and animal species are adapted to specific temperature and moisture conditions. When the climate becomes warmer, cooler, wetter or drier, these species must adjust or perish. Species can do two things to adjust: they can physically move or they can physiologically adapt by evolving rapidly. Whether a species can successfully adjust to changing conditions depends on many factors. How fast is the climate changing? Are there suitable alternative habitats adjacent to the current habitat where the species can move as the climate changes? Can the species move at all (tree species take generations to move their ranges)? How fast can the species evolve in order to live under different conditions? Generally, the faster the pace of climate change, the less chance a species has for successfully adjusting. For example, like all cold blooded species, lizards need to be surrounded by warm temperatures or their bodies cannot operate. If it gets too hot, however, lizards can overheat. Once the temperature hits a certain level, lizards seek shelter and put off their activities, which leaves less time for things like gathering food or finding mates. In the hills of southern Mexico, there has been an increase in temperature since the mid-1970’s and a corresponding increase in the number of hours where high temperatures restrict lizard activity. The increase in temperature was greatest during the late winter and spring seasons, when mating occurs. Sites with particularly high temperature restrictions – and thus sites where mating was discouraged – tended to be sites where extinctions occurred during this 30 year period, despite the  fact that habitats remained intact. Twelve percent of local lizard populations went extinct during this period.

Seasons: Winter, Spring, Summer, Fall

Source: Sinervo, B et al. “Erosion of Lizard Diversity by Climate Change and Altered Thermal Niches.” Science 328 (2010): 894-899.

Trivia Question: As temperatures have warmed over the past 40 years, the area of the Green
Mountains dominated by pines has…

a. shrunk
b. expanded
c. remained about the same

The correct answer is a. A two degree Fahrenheit warming and a 40 percent increase in precipitation in the region over the past 40 years has corresponded to shrinking of the area dominated by conifer trees and range expansion of the less cold hardy broadleaf trees. The area of the mountains dominated by broadleaf forests increased by 19 percent.

Seasons: Winter, Spring, Summer, Fall

Source: Beckage, B. et al. “A rapid upward shift of a forest ecotone during 40 years of warming in the Green Mountains of Vermont.” PNAS 105 (2008): 4197-4202.

For comparison: When the stalagmite began to grow, the Roman Empire was beginning its long process of decline. In modern day California, the Grizzly Giant Sequoia tree in Yosemite National Park was just sprouting. Modern Hinduism was established in India around this time.

Seasons: Winter, Spring, Summer, Fall

Source: Zhang, P et al. “A Test of Climate, Sun and Culture Relationships from an 1810-Year Chinese Cave Record.” Science 322 (2008): 940-942 and Kerr, RA. “Chinese Cave Speaks of a Fickle Sun Bringing Down Ancient Dynasties.” Science 322 (2008): 837-838.

For comparison: 229 trillion gallons is about double the amount of water in Lake Erie.

Seasons: Spring, Summer, Fall

Source: Neal, EG et al. “Contribution of glacier runoff to freshwater discharge into the Gulf of Alaska.” Geophysical Research Letters 37 (2010): LO6404.

How changes in the carbon cycle affect Earth’s temperature and how Earth’s temperature affects the carbon cycle are two key questions for climate research. In 2008, there was a net release of about 98 petagrams (98 billion metric tons) of carbon from the soil into the atmosphere. Since 1989, there has been a 0.1 billion metric ton increase in this annual amount of carbon released from the soils. A key question is whether this increased release is in the form of newly mobilized “old” carbon that had been stored in the soils or whether the soils are also taking up more carbon from the atmosphere and there is more “new” carbon that is being cycled at a faster rate. “New” carbon being cycled at a faster rate would imply a general acceleration of the carbon cycle.

Seasons: Winter, Spring, Summer, Fall

Source: Bond-Lamberty, B and Thomson, Allison. “Temperature-associated increases in the global soil respiration record.” Nature 464 (2010): 579-582.

Over the past few centuries, large parts of North America were converted from native ecosystems to agricultural and urban landscapes. Agricultural land now covers about 17 percent of America’s surface. One of the most intensively farmed areas is California, which grows about half of America’s domestically consumed produce. As the number of farms in California grew between 1934 and 2002, the amount of irrigated land grew as well. At weather stations located in the State’s agricultural centers, the irrigated proportion of the surrounding landscapes grew from 22.4 to 62.2 percent. Large irrigation systems, which provide vital water to crops in California’s Mediterranean climate where almost no rain falls in the summer, can increase evaporation and cloud cover, ultimately having a cooling affect. Compared to other California weather stations where large increases in irrigation did not occur, daily maximum temperatures decreased by 3.6 degrees Fahrenheit between 1934 and 2002. Because daily minimum temperatures showed little trend at these stations during this period, the average daily temperature range, or the difference between the daily maximum and daily minimum temperature, became smaller.

Seasons: Spring, Summer

Source: Lobell, David B., and Celine Bonfils. “The Effect of Irrigation on Regional Temperatures: A Spatial and Temporal Analysis of Trends in California, 1934-2002.” Journal of Climate 21 (2008): 2063-2071.

Phenology is the study of naturally recurring events, such as plants blooming in spring. In moist temperate regions like the Eastern United States, some plants come out of their winter dormancy once temperatures become sufficiently warm – which is usually once there is a certain number of cumulative hours with ambient (air) temperatures above a certain threshold (such as 50 hours over 50 degrees Fahrenheit during a ten day period). Other plants will only respond to a temperature signal once there has been a certain number of winter “chill hours,” or a set amount of hours during the cold season when temperature are near or below freezing. Other plants unleash their flowers and leaves when the days become a certain length – such plants are said to be “photoperiod controlled.”  Depending only on temperature as an “alarm clock” is risky for a plant. This is particularly true in regions with variable weather regimes, where the transition from winter to spring can mean several days of temperatures in the 60s that are soon followed by a cold front and a few days of freezing temperatures, which can potentially damage a plant’s young leaves or flowers. Photoperiod and chill hour “alarm clocks” keep plants from sprouting their sensitive leaves and flowers at the wrong time. Because different plants use different “alarm clocks,” not all species respond to warming temperatures in the same way. Most plants and animals do appear to be responding to warming temperatures, with most species at temperate latitudes advancing their spring activities by 2.5 days per decade since 1970.

Season: Spring

Sources: Korner, C and Basler, D. “Phenology under global warming.” Science 19 (2010): 1461-1462 and Menzel, A et al. “European phenological response to climate change matches the warming pattern.” Global Change Biology 12 (2006): 1969-1976.

Trivia Question: Since 1970, Earth’s “green” seasons have become…

a) longer  
b) shorter

The correct answer is a. Earth’s “green” season – the combined average length of both the Northern and Southern Hemisphere green seasons – is now on average 15 days longer than it was in 1970. This trend has been linked to warmer temperatures, milder winters and higher concentrations atmospheric carbon dioxide.

Seasons: Late Winter, Early Spring

Source: Peñuelas, J et al. “Phenology Feedbacks on Climate Change.” Science 324 (2009): 887-888.

Trivia Question: During El Niño years such as this year, when the eastern tropical Pacific is relatively warm, does the Great Basin region have on average…

a. fewer frost days?
b. more frost days?

The correct answer is a. All other things being equal, the Great Basin region experiences fewer frost days during El Niño years compared to La Niña years.

Seasons: Late Winter, Early Spring, Fall

(Sources: Meehl, GA et al. “Current and Future U.S. Weather Extremes and El Niño.” Geophysical Research Letter 34 (2007) L20704 and Easterling, David. “Observed Climate Variability and Change.” NOAA/National Climatic Data Center. Ashville, NC: 31 January 2007 http://www.ametsoc.org/atmospolicy/documents/Easterling-Observed-Change-Jan-07.pdf)