Trends in the Ocean

Introduction: The Ocean's Rising Sea Levels

1 CE

The rate of rising in sea levels has increased at an alarming rate in recent years. The global mean sea level was 3.2 inches (81 millimeters) above the 1993 average in 2018. Additionally, it was the highest annual average on satellite record (1993-present). These rising sea levels are contributed by both meltwater from glaciers and ice sheets, as well as thermal expansion of the water as its temperature increases.
(www.climate.gov)

Human Impact and CO2 Emissions

2

Industrialization, urbanization, deforestation, and more have contributed to the rising levels of atmospheric CO2 over time. Thus, as more fossil fuels are burned, more CO2 is being released and the amount of absorbed CO2 is decreased (from deforestation). According to the NOAA, an estimated 50% of CO2 stays in the atmosphere, 25% is absorbed by plants, and the other 25% is absorbed by areas in the ocean where the concentration of CO2 is lower than in the atmosphere.

The Greenhouse Effect

3

Increasing ocean levels are directly linked to a phenomenon called the greenhouse effect. In this process, some solar radiation rays are reflected and some are absorbed into the atmosphere. Then, this energy is absorbed by land and oceans and when this radiates towards space, some is trapped by the greenhouse gasses. Therefore, when human activities such as burning fossil fuels and urbanization increase, atmospheric CO2 increases and more heat is retained in the atmosphere.

Humans and the Greenhouse Effect

4

Carbon emissions contribute to larger carbon footprints, contributing to the Greenhouse Effect. This is both positive and negative. On one hand, greenhouse gases in our atmosphere trap heat and help our planet be inhabitable. However, if there are too much of these gases in our atmosphere (such as CO2), it makes it harder for heat to escape our atmosphere, causing the Earth to heat up. This affects the oceans, causing thermal expansion and rising sea levels.

Heat and the Oceans

5

As more heat and CO2 are trapped in the atmosphere, the oceans absorb more CO2 because the concentration of CO2 in the ocean is less than that in the air (similar to thermal equilibrium), warming the oceans. Since water molecules move more when they are heated, high water temperatures expand the ocean waters (thermal expansion). Additionally, more CO2 absorption changes the chemistry in the water, increasing levels of carbonic acid, making the oceans more acidic and impacting marine life.

Effects on Animals

6

Many marine organisms are impacted by warming oceans. These include calcifiers such as corals and sea urchins because a higher amount of carbonic acid increases the number of hydrogen ions and bicarbonate, which makes it harder for calcifiers to use calcium carbonate for their shells. This affects the other organisms in their ecosystem as well (such as algae, which live in corals). Moreover, warming oceans also melt glaciers and ice sheets, impacting arctic ecosystems and raising water levels.

Effects on Humans

7

According to (climate.gov) by the National Oceanic and Atmospheric Administration(NOAA), nearly 40% of people in the U.S. live in "high population-density coastal areas". In these coastal city settings, higher water levels could damage infrastructure, impacting jobs, residential areas, and many more. It could also mean that storm surges travel farther than they did in the past. On top of this, disruptive-and expensive-'nuisance' flooding will occur more often (300-900% more than 50 years ago!).

Summary

8

Rising sea levels are mainly due to more CO2 emissions that raise the Earth and ocean temperatures, causing thermal expansion and melting glaciers/ice sheets. This warming, rising ocean impacts humans and animals. This relates to the coyotes in the city because if humans choose to build more inland, coyotes have less space to live, causing more frequent coyote appearances. Both situations show that if Earth is put into imbalance, the environment/life around us will be put into imbalance as well.