Ecology: Introduction to Climate Change
Glacier Debate
It is not yet known how much of the retreat is due to global warming that previously occurred and caused unstable conditions or how much is owed to the recent warming of Earth.
Atmosphere and Captured Energy
62% of the thermal radiation absorbed by the atmosphere warms Earth. The other 38% is turned back to space.
Edith's Checkerspot
A butterfly that is endangered and native to California. It is rare and lives in localized colonies and is closely associated to its larval food source: dwarf plantains and Indian paintbrush.
Keeling Curve
A figure produced by Charles Keeling's studies in Hawaii that shows the variation in atmospheric carbon dioxide since 1958. It is credited as the first to bring to the attention that human activity is affecting Earth's atmosphere (shows a positive trend in atmospheric CO2).
Muir and Riggs Glacier
A glacier duo also of Alaska, though these are located in Glacier Bay National Park and Preserve. In 2004, the Muir glacier was noted to have retreated out of much of its 1941 area, where it was as thick as 65m in come areas. Riggs glacier has retreated 3 km as opposed to Muir's 20 km.
Pedersen Glacier
A glacier in the Kenai Fjords National Park. Since 1920, the glacier has declined to a period in 2005 where a grassland has taken up residence where this glacier and its lagoon once sat.
Elevation and Habitat
As a result of the rain shadow and elevation, temperature and rainfall increase as you go up a mountain. This causes specific vegetation communities to appear at different elevations on the same mountain.
Changes in the Antarctic Ecosystem
As a summary, as the Antarctic is warming, the pattern of sea ice formation is changing (being made less available).
Temperature and Latitude
As latitude decreases, temperature increases as you move from the poles to the tropics. Climate change is predicted to cause isotherms to shift to more northern latitudes (poleward) so that more Northern Latitude experience higher temperature.
Altered Habitats Due to Climate Change
As the climate changes, temperature and rainfall patterns are predicted to change with elevation, no doubt causing a shift in the vegetation communities. The scenario shown for example indicates that a 3.5C and 10% change in temp and precipitation respectively would cause huge shifts in vegetation communities. Paleologic evidence show this has happened before, so it can most likely happen again.
Rain Shadow
As we remember, a rain shadow effect occurs when a moist air current rises along a mountain side: the cooling of the air causes precipitation as the current can no longer hold moisture. Once the current reaches the other side of the the mountain, it no longer has any moisture left.
Changes Due to Warming
Density changes, range shifts, phenology, morphology/behavior, and frequencies.
Earth's Climatic Variation
Caused by the uneven heating of the surface by the Sun. The spherical shape of the earth combined with the angel at which it tilts contributes to this.
Recent Rise in Sea Level
Data of the annually averaged sea level at 23 geologically stable sites with long term records shows a rise in sea level. Specifically, the data indicates a rise of 18.5 cm or 7 inches in roughly the last 100 years in the three year average. Many attribute this to global warming.
Global Temperature Trends
Data shows that at the same time that carbon dioxide was increasing in the atmosphere, so was mean temperature. Since the 1980s, the Earth has become consistently warmer than average: Over the past 100 years, the average temperature has increased by 0.6 C.
Northern Hemisphere Snow Cover
Decade averages in snow cover found between March and April in the Northern Hemispheres shows a decrease in snow cover of North America since 1950.
Annual Variation in Antarctic Sea Ice
Every year, a large ice sheet forms and thaws across and extending from the continent. At the end of summer it is small, but at the end of winter it is fairly large. Algae grows under this ice.
D.C. and the Cherry Blossoms
Festivals are planned for the peak bloom of the cherry blossoms. However, because of the climate change, the bloom comes earlier and earlier each year: now it is 5 days earlier than it was 30 years ago, even though the festival dates are the same.
Shift in Location of Suitable Habitats
From the change in butterfly distribution, we can assume that the southern latitudes and lower elevations have now become unsuitable to live in.
Ice Algae
In order to survive, krill larvae must constantly eat. Sea ice is particularly advantageous for them in that it will shelter them and provide algae that grows on the underside for them to eat. The message here is that the ice is essential to juvenile krill.
Krill
Krill are an incredibly important food source of many animals in the Antarctic, including many fish, whales, and even penguins.In the last thirty years, krill population has also declined much like the penguins. However, krill decrease is as high as 80%.
Krill Life Cycle
Krill live for about 5 to 6 years. During the breeding seasons from December to March, and hatch in the depths rather than at the surface. Juvenile krill grow in the winter where their primary food item is ice algae.
Analysis of Climate Impacts on Species
Many studies have concerned themselves with looking for evidence that the climate change has had an effect on living organisms. By 2006, 866 studies concerning more than 1500 species have found a change on biota.
The Greenhouse Gasses
Methane and nitrous oxide are the 2nd and 3rd most significant gasses, both of which are mostly produced due to agricultural process (Fuel processing and waste disposal for methane, too). Carbon Dioxide is the most significant however.
Of the Climate Impact Studies...
More than 80% of the species studied exhibited changes that would be predicted to climate change. Furthermore, authors also identified changes that would be predicted due to warming.
Shift in Phenology
On average, plants and animals have shifted phenological 5.1 days early on average per decade. Trees, however, have not shifted much in phenology. Contrarily, birds, some of which are pollinators, have shifted closer to 6 days on average.
Phenology in Perspective
Organisms take advantage of the predictable seasonal cycles to "time" certain natural events when they would be most favorable. This is a product of evolution. Examples of this would be the migration of birds before the coming of the winter or the blossoming of the flowers just after the last freeze.
Latitude and Extinction
Patterns of Edith's checkerspot show an extinction of many populations in the Southern latitudes (except at mountain ranges in the higher altitudes) between 1860 to 1983.
Antarctic Temperature
The western Antarctic peninsula has registered the largest increase in temperature on the planet! It's temperature has increased almost 6 degrees C over the past 50 years.
Annual Use of Greenhouse Gasses
Power stations and industrial processes release the most greenhouse gases. In addition, 72% of the gases are carbon dioxide, 18% are methane, 8% nitrous oxide, and 1% are other gases.
Range Shift and Root et al.
Range shift is another impact of of climate change. Root predicted that the range of species might shift poleward or up in elevation to find areas that suit their metabolic tolerances.
Trophics Levels and Krill
Since many carnivores depend on krill and high-order carnivores depend, in turn, on these carnivores, a reduction in ice algae causes a disruption of population of krill. Less krill means less penguins if they cannot find anything else to eat, again, lower their population and the higher carnivores.
Penguin Density Changes
Since the 1970s, emperor penguins have seen a decline of almost 50% of breeding pairs in certain parts of Antarctica.
Krill and the Sea Ice Importantce
Summer food and the extent of winter sea ice are thus key factors in the high krill densities observed in the southwest Atlantic Ocean. Krill need the summer phytoplankton blooms of this sector, where winters of extensive sea ice mean plentiful winter food from ice algae, promoting larval recruitment and replenishing the stock.
Krill and the Sea Ice: Temporally
Temporally, within the southwest Atlantic, summer krill densities correlate positively with sea-ice extent the previous winter.
Summary of Camille's Butterfly Study
The change in temperature and rainfall in the Southern latitudes and low elevations has caused the food plants of the butterflies to die earlier; in fact, too early that the larva have not finished development. Therefore, the butterflies can no longer live in this environment.
Krill and the Sea Ice: Spatially
The changes in ice formation have had a major effect on krill. Spatially, within their habitat, summer krill densities correlate positively with chlorophyll concentrations.
Cherry Blossom and Flowering
The cherry blossom is an important cultural symbol in Japan. As such, the records of when they blossom are very well kept. It was not until the early 1900s that significant variation was seen in the flowering time. Since that time, there has been a steady advancement of earlier flowering time following 1952.
Greenhouse Effect
The effect caused by rays from the sun in which they reach the Earth's surface, are radiated from Earth, but then are captured by "greenhouse gases." This effect is what keeps Earth's surface at 14 degrees Celsius. 75% of the surface heat captured by Earth is because of these gasses.
Benefits of the Greenhouse Effect
The greenhouse effect is actually natural and beneficial: without it the Earth's avg. temperature would be -18 degrees Celsius!
Pollinators and Phenology
The mismatching of phenological timing can harm important functions like pollination because, similar to the butterflies, the food plant can end up dying to early and upset the natural process.
Carbon Dioxide
The most important of the greenhouse gasses that makes up 0.038% of Earth's atmosphere. 72% of all greenhouse gas emissions are carbon dioxide, mostly through the burning of fossil fuels: easily the leading cause of global warming.
Phenology
The study of the timing of natural events.
Review of All Range Shift Studies
There have been long-term range shifts in 30 different regions encompassing over 700 different species.The studies indicate that organism distribution is moving northward at 17 meters per decade and to higher elevation at 11 meters per decade.
Antarctic Food Web
To understand why the penguins are in decline, one must understand the dynamics of Krill, which form the base of the food web in the Antarctic.
Effect of Antarctic Temperature Change
Typically, ice formation starts in the coldest areas of the coasts in late March or early April and works its way up the coast. Now, however, the ice is forming two or even three weeks later. Also, heavy sea ice only forms 1/2 years out of every 5 years rather than 4 of every 5.
Data of Cherry Blossoms from Mt. Takao Japan
Unique in that this set contains both temperature and phrenological data. Peak flowering date has progressed to an earlier date, and average temperature for Feb-Mar has steadily increased.
CO2 as Measured by Ice Cores
Using ice cores, we can see the variation in atmospheric CO2 for the last 400 thousand years. This is because large changes in CO2 can be related to glacial/interglacial cycles within an Ice Age (Ice Age Cycles).
Ice Age Cycles and Cores
While glacial cycles are are mostly related to a change in Earth's orbit, those changes influence the carbon cycle which will then also affect the glacial system. Since the beginning of the industrial revolution, the burning of fossil fuels has caused a rise in CO2 not yet reached by any previous cyclic spike in CO2.
Food Web Summary
With population reductions, either carnivores find a different source of food or they begin to die off.
