A variety of events in the past year have triggered scientists to question whether climate change is a reality and whether it's a result of global warming.
Ocean "Dead Zone"
In the Pacific Ocean, off both the coasts of Washington and Oregon, scientists saw an increase in marine bird deaths last year. Scientists attribute those deaths to a lack of plankton and lack of fish as a result.
The cause, scientists say, is an increase in ocean water temperatures.
Coastal ocean water temperatures were anywhere from 2 to 5 degrees above normal along the Washington coast and 8 to 11 degrees above normal along the Oregon coast in 2005, according to a report by Oregon State University.
That increase has been attributed to a lack of ocean "upwelling" - a process by which cooler water, rich with nutrients, rises from the ocean floor and mixes with the warmer water near the surface, the report says.
The upwelling process usually begins in the late spring, but last year, upwelling didn't begin until July, causing chlorophyll levels, a measure of the waters productivity, to be just one-sixth of normal.
This lack of chlorophyll, which plants use to make food through photosynthesis, creates a "dead zone" in the area because the food chain begins to break down, scientists contend.
Too much upwelling, however, can have a negative effect on the ocean as well.
It creates a lack of oxygen in the water, which leads to the suffocation of animals who cannot breathe in the oxygen-depleted water. This creates a different type of dead zone.
How does all this relate to global warming?
Ronald Neilson, a botany professor at OSU, says the upwelling cycle is consistent with the expected effects of global warming.
"We can't yet prove that the ocean changes you are seeing in the Pacific are the result of global warming," Neilson said.
But Neilson said there is strong evidence that long-term climate change is the result of global warming. And climate change is the reason why upwelling has occurred so inconsistently in past years.
These dead zones also occurred in 2002 and 2004, the report said. Dead zones that occurred in those years were the result of an over abundance of plankton which consume oxygen. Fish, crabs and other sea life literally suffocated in the oxygen-depleted water.
Scientists contend that climates are a delicate mix of different atmospheric and weather patterns, and it doesn't take much to throw those weather patterns off.
Neilson says global warming will increase high pressure systems and will cause other weather systems to become more intense.
"The oceans and land are all part of the same planet, and what affects one will also affect the other," he said.
As a result of increases in ocean temperature, ocean currents may be increasing, along with other mechanisms that help to distribute ocean temperatures, scientists say, and these could be long-term changes that could last for decades.
If you think the sun has looked brighter lately, that might be because it is - or at least because more of the sun's radiation is reaching the ground.
According to a study done by the University of Oregon, more sunlight is reaching the Earth's surface than in recent years.
That means the amount of the sun's energy that's hitting the ground has the possibility to increase surface temperatures.
Scientists say this problem, called "global brightening," is a result of efforts in the past decade, to clean up smog in areas of the country, and all over the world.
Industrial collapse in the former Soviet Union, along with stricter air standards in other parts of the developed world, have helped clean up air quality, scientists say.
The resulting improvement in air quality has reduced the effect's counterpart, "global dimming." Smog and other air particulates were thought to be blocking sunlight and reducing temperatures in heavily polluted areas, but scientific data collected over the past several years refutes that claim.
Data collected from 1960 to about 1990 showed a 4 to 6 percent decrease in radiation from the sun reaching the ground.
But data from the past 10 years has shown a different trend, according to researchers.
Data from the University of Oregon has shown an increase of half a watt per square meter in total energy reaching the ground.
Other studies have shown similar results.
"When we looked at the more recent data, lo and behold, the trend went the other way," said Charles Long, a scientist at the Pacific Northwest National Laboratory, based in Richland.
The PNNL, a Department of Energy facility, has also done research in this area. Their report shows an overall increase of 4 percent in radiation from the sun reaching the ground in the past 10 years.
Increases were recorded on every continent with the exception of South America, where recording stations actually showed a decrease in radiation reaching the ground.
That decrease could be attributed to many things. Lax regulations on industrial emissions, and deforestation and extensive burning of rain forest trees are two possibilities.
Monitoring stations on the continent are also not as accurate as on other continents, which could contribute to the PNNL's findings.
But with increases in surface temperatures, the report says global brightening may finally increase atmospheric temperatures the way scientists have predicted global warming would.
"The atmosphere is heated from the bottom up," Long said.
Additionally, NASA scientists have found that Earth's albiedo - the amount of light it reflects back into space - is shrinking. Using satellite data, NASA found that more radiation is hitting the ground, rather than being reflected back into space by snow and ice.
This suggests that the polar ice caps have been reduced in size; another sign of increasing temperatures, and global warming.
Air stagnation in the West
With increases in temperature will come a reduction in air quality, a computer simulation by PNNL funded by the Environmental Protection Agency, is predicting.
By 2050, areas west of the Rocky Mountains will see an increase in the number of stagnant air days per season.
Stagnant air days occur when air sits over an area of land for a period of time and fills with dust particles and ozone.
Higher temperatures, up by as much as four degrees Celsius, could be seen in the western part of the country.
That increase could mean high temperatures in July, Sunnyside's hottest month, could jump from about 90 degrees Fahrenheit to 96 degrees Fahrenheit on an average summer day.
Though air stagnation will increase throughout the country, the western part of the country will see the worst of it with a doubling of poor air quailty days per year.
Currently, Western states see about a week's worth of "stagnation events."
Though ozone protects us from ultraviolet radiation in the upper atmosphere, in the lower atmosphere it's partly responsible for the presence of smog.
The model predicts Western states will see two weeks worth of bad air days in the period between 2045 and 2055.
Factored into the computer model were known variables, including air temperature, cloud cover and solar radiation.
Though the model predicted an increase in bad air days, they're limited to the fall, the PNNL report states. Other seasons will continue to see normal air stagnation in the West.
Some states and areas of the country, however, are in stark contrast to the West.
Texas, for example, will see a 2 or 3 degree Celsius increase in temperature and a four-day increase in bad air days.
"It's not a large change compared to the average 15 days per season in the control simulation," said Ruby Leung, a scientist with the PNNL, in the lab's report.
The control refers to what is predicted based on unchanged atmospheric conditions associated with global warming.
That means the model doesn't show a significant change for the Southwest.
Leung said the West should expect to see the largest change based on results of the model.
The Midwest, according to the model, will buck the trend of global warming.
The area will see a possible decrease in temperatures if the model holds true. An increase in the area's cloud cover will reduce air stagnation by as many as eight bad air days a year, and increase the amount of rainfall the area receives by as many as six days, the model says.
"More studies need to be performed by including projections of natural and [human-produced] emissions," Leung concluded in the PNNL report.