Positive Feedback Loops
Definition: A loop that enhances or amplifies changes. They tend to move a system away from its equilibrium and makes it more unstable.
Example: World population growth. A large population has a large amount of babies. Those babies in turn make the population larger. That population then has more babies which leads to bigger population. That leads to even more babies, etc.
Climate change is an example of a positive feedback loop because as the earth heats up, the ice melts. As the ice melts, trapped gases are released into the air cause the greenhouse effect. That warms up the earth more which melt more ice, which releases more gas. Greenhouse effect is worsened, more heat, less ice, more gas, etc.
Ice Cores: Ice samples from the ice sheets in Greenland, Antartica, and North America. The water molecule isotopic compostions in ice cores help determine past temperatures. Air bubbles in the ice contain trapped greenhouse gases that are helpful in determining past climate changes.
Tree Cores: More commonly known as tree rings. Wider tree rings when conditions favour growth and narrow when conditions are rough. These help determine regional and global climates from years past.
Ocean Sediment: Study of the oxygen isotopes within the ocean sediment. They are influenced by summer temperature, winter snowfall, and rainfall in particular regions.
Coral: Skeletal rings are similar to tree rings. Stable oxygen isotopes in the calcium carbonate of the coral determine temperatures. Colder temperatures tend to cause heavier isotopes while war temperatures are more normal oxygen isotopes. Denser water salinity also tends to result in a heavier isotope.
Pollen: An abundance of pollen of a certain vegetation time depends (partially) on weather conditions of previous months. So pollen density provides information on more immediate climatic conditions.
The earth's average global temperature has increased by about 0.8 degrees Celsius since 1880.
Temperature changes can affect both plant and animal lifestyles. Too hot of a climate can disrupt plant photosynthesis and reproduction. As the temperature rises, forest fires are more numerous, killing plants faster. Animals can't survive in certain temperatures so as things get warmer they migrate to colder regions, disrupting the life cycles of many environments.
Sea Level Changes
Overall, the sea level rise is about 20 centimeters since 1901.
As the sea level rises, it destroys the coasts. Seawater erodes coast far too fast, floods wetlands, contaminated aquifers/soils, and destroys habitats for coastal birds, animal, and plants.
Higher sea levels can result in more powerful storm surges. Human establishments will be more vulnerable to flooding. Forcing them to move inland, crowding areas and forcing more animals out of their habitats.
Changes in Precipitation
One obvious example is California. Too many people live there and with global warming, water levels were dropping far to fast, resulting in a severe drought. Suddenly it started raining too much rain.
As the earth gets warmer, more water is evaporated. That leads to more rainfall and snowfall but also means heavy downpours. Those can lead to destructive erosion and flooding of areas.
Changes in Global Ice
As the earth warms, ice melts faster than it can be replenished. This can lead to warming ocean water temperature, more extreme weather, and raising sea levels dangerously high. Less ice can lead to faster global warming.
If the Greenland Ice Sheet melts completely it can contribute an a rise in the sea level by 20 feet.
Changes in Biota
Plants start flowering earlier in the year. Freshwater phytoplankton and zooplankton blooms are also occurring earlier. Other plants/animals are migrating upward searching for colder temperatures. This could lead to extinction if they can't find the proper climates.
As more and more animals migrate northwards, less biodiversity is spread around. Those areas become bereft of plant and animal life, worse than a desert. Animals will be forced in the same regions, resulting in increased competition and faster extinction of species that can't adapt/win.
Industrial and Photochemical can both choke an environment. The lung problems the cause in humans can kill us. China has the worst case of smog which results in higher levels of asthma and other lung-related diseases. Smog can also affect plants. Smog blocks the sun, limiting the amount of plants that can survive in smog entrenched regions.
Solutions to climate Change