Climate Change and Human Impact

Many natural processes cause climate change Volcanic eruptions – volcanic ash and dust in the atmosphere reflect solar energy and can lower temperatures These are short-term changes

Ocean circulation – changes in ocean circulation cause short-term changes in precipitation (El Niño and La Niña) Solar activity – sunspots have been connected to warm periods in Europe and North America

Earth motions – Plate movements and changes in the Earth’s tilt and orbit cause large climate changes changes are long-term

How do humans impact the environment? Humans have a large impact on the environment and the organisms we share it with. This is due to our –Increasing population size. –Increasing use of both renewable and non-renewable resources.

The Carbon Cycle Cycling of carbon through the environment mainly in the form of CO 2 and carbohydrates.

What processes remove carbon dioxide from the atmosphere? Photosynthesis by land and aquatic autotrophs Precipitation onto land & ocean

What processes release carbon dioxide into the atmosphere? Cellular respiration by all organisms Decomposition of organisms Volcanic activity Human activities

What stores carbon dioxide? Limestone (calcium carbonate) rock Decomposition of organisms and their conversion into fossil fuels Diffusion of carbon into the ocean

The Carbon Cycle

Human Activity and the Carbon Cycle Human activity causes the release of CO 2 at a much faster rate than it is absorbed. This is due to: –Clear-cutting and burning forests for housing and farming –Burning fossil fuels These activities have resulted in a global climate change.

What is the Greenhouse Effect? Works like a car in the summer. Sun passes through, hits a surface and changes to heat. Heat is trapped.

What is the Greenhouse Effect? The greenhouse effect is the natural warming of Earth due to certain gases in the atmosphere trapping out-going heat energy. Greenhouse gases - water vapor, carbon dioxide, & methane

Global Warming

So then what is Global Warming? The Greenhouse Effect and Global Warming are NOT the same thing!!! Global Warming is the increase in the average measured temperature of the Earth's near-surface air and oceans. Global Warming affects the Greenhouse Effect. –Greenhouse Effect = GOOD – Global Warming = BAD

What are the Possible Effects of Global Warming? These include: Flooding of coastal areas. Increased spreading of disease. Drought across inland areas.