Essay
Suggest why the Earth’s climate naturally varies
- Course
- Institution
Suggest why the Earth’s climate naturally varies [6].
[Show more]
Seller
Follow
mnbvcxzlkjhgf
Reviews received
Content preview
CLIMATE CHANGESuggest why the Earth’s climate naturally varies [6]
Natural forcings, which induce change in the climate system may be external or internal. External
forcings include shit in Earth’s orbit, axial tilt, precession of the equinoxes & also fluctuations in solar
output. These forces control the distribution of solar radiation on the planet’s surface. Internal forcings
also play an important role in global climate change & these include volcanic eruptions, continental
drift, changes in ocean circulation & fluctuations in atmospheric CO2. The concentration of GHG
which traps solar radiation in the atmosphere is a natural occurrence. There’s a relationship between
atmospheric CO2 levels & average global temps. Periods of icehouse Earth, such as the past 3
million years, correspond with low levels of CO2 in the atmosphere which reduce natural greenhouse
effect. Milankovitch cycles also influence the Earth’s climate. It consists of obliquity which is the tilt of
Earth’s axis. Earth’s axial tilt varies from 22-24.5° and when tilt is close to 22°, seasonal temperature
differences are reduced & thus summers are cooler & winters are warmer which means snow
accumulated during winter doesn't melt in summer so glaciers & ice sheets expand. The eccentricity
of orbit varies from near circular to elliptical. With maximum eccentricity, differences in solar radiation
receipt of around 30% occur between perihelion (when Earth is closest to Sun = more insolation) &
aphelion (when Earth is farthest from Sun). Precision of equinoxes is when the Earth rotates on its
axis, so that the point in the Earth's orbit when it’s closest to the Sun (perihelion) changes over time &
this affects the intensity of seasons. If perihelion occurs during the northern hemisphere's winter,
winters will be warmer & summers cooler. Snow & ice accumulating in winter will not melt so snow
cover expands, eventually triggering a glacial period. Volcanic eruptions also influence climate as
eruptions pump huge amounts of volcanic ash & sulphur dioxide which has a cooling effect. The
aerosols can be moved around by winds & cause significant cooling worldwide. E.g Mount Pinatubo
eruption in Philippines which cooled Earth's climate by 1.3°C
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller mnbvcxzlkjhgf. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.91. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
64438 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now