IB Geography Causes of Global Climate Change

Insolation

Incoming solar radiation

Short vs. Long Wave Radiation

Insolation = shortwave radiation, easily passes through greenhouse gases, re-radiated = longwave radiation, harder to pass through

Energy Budget

How insolation is absorbed and re-radiated, net positive absorption of energy

(Natural)Greenhouse Effect

GHGs(CO2, CH4, N2O, H2O) form a blanket. Raise average temperature by 33° to 15°.

(Natural)External Forcing

Influence on the earth system by solar radiation. Variations in earth orbit, changes in solar radiation, changes in atmosphere composition all fall under this.

(Natural)Volcanoes: Carbon Dioxide

CRAP collects at the bottom of oceans. At convergent boundaries, it becomes CO2 and is released in explosions

(Natural)Volcanoes: Global Dimming

Ash(sulfur-rich particles) block insolation and reduce global temperatures.

(Natural)Croll-Milankovitch Cycles

Earth's orbit becomes more eccentric every 100,000 years(gravity of lining-up planets). Causes Ice Ages when orbit is most eccentric.

(Natural)Sunspots

Areas of high magnetic activity. Solar flares cause increase solar radiation. Peak over approx. 11 years.

(Natural)Cloud Coverage

Increased temperatures → increased evaporation → increased cloud coverage → decreased insolation → decreased temperatures

(Anthropogenic)Albedo Effect

Temperatures increase → ocean water warms → polar ice melts → albedo is decreased → more absorbed insolation → temperature increase

(Anthropogenic)Permafrost

Temperature increase → permafrost melts → organic matter decomposes → CH4 released → temperature increase

(Anthropogenic)Deforestation

Releases CO2 + decreases photosynthesis + clears land for industrial use

(Anthropogenic)Energy

Hydrocarbons used as fuel

(Anthropogenic)Livestock

Ruminants produce methane + deforestation + water use + shipping + soil degradation

(Anthropogenic)Plant Agriculture

Pesticides and herbicides can run into water sources and damage ecosystems. Fertilisers can run into water sources and cause eutrophication

(Anthropogenic)Transport

Combustion of fossil fuels produces CO2 and well as other harmful gases. 27% of US GHG emissions are caused by transport. Growing issue as more people in developing countries can afford vehicles.

(Anthropogenic)Industry

Fossil fuels are used for heat, power, or chemical processes