natural causes of climate change

Question 1

describe the climate change happening on earth

Answer 1

there is plenty of evidence that earth’s climate has changed over time

recently earth has been warmed rapidly- at around 1.7 degrees per century-due to human activity

Question 2

what are the natural causes of climate change?

Answer 2

for most of the earth’s history climate has changed due to natural processes. it has gone through warmer periods and colder ones. the ice ages, the natural causes include changes in:
- the amount of solar energy
- volcanic activity

Question 3

volcanic eruptions and climate

Answer 3

volcanoes are constantly erupting somewhere in the world. from time to time large-scale eruptions occur which can temporarily change the climate

large explosive eruptions can send ash and gas high up into the atmosphere, where they are dispersed by winds around the globe.

the particles reflect sunlight away from the earth so that the climate cools for months or even years

Question 4

describe Tambora and the year without a summer

Answer 4

tambora is a large volcano in indoesia. its eruption in 1815 was the most explosive ever recorded. it blasted the top off the volcano, creating a huge caldera (below). it released 150km3 of ash and gases into the atmosphere

Question 5

how many people died in tamborar

Answer 5

locally about 10,000 people were killed directly by ash, gases and volcanic bombs, and another 80,000 by diseases and hunger

Question 6

how far did the ash cover

Answer 6

the ash column reached 44km into the stratosphere. high-level winds quickly spread fine particles around the world, blocking out the sun

Question 7

what was the result of this volcano

Answer 7

as a result of the eruption, the global temperature fell 0.5 degrees on average. in Europe 1816 was the year without a summer, crops failed, and famine and disease were widespread.

Question 8

how much energy will reach the surface of the earth

Answer 8

1360 watts per m2 of solar energy reaches the top of the earth’s atmosphere but this is an average. the solar output changes over an 11-year cycle.

Question 9

what is one sign of this cycle

Answer 9

one sign of this cycle is sunspot activity. more sunspots coincide with slightly more solar radiation and fewer sunspots with less radiation.

Question 10

when have their been low sunspot activity

Answer 10

since 1980 there has been a decline in sunspot activity

periods of low sunspot activity have lasted longer in the past e.g in 1450-1550 and 1645-1715 the little ice age.

during these periods they are very little to no sunspots on the suns surface and so temperature decreases

Question 11

how often does the suns brightness increases

Answer 11

for every 1 billion years, its brightness increases by about ten per cent

Question 12

how does the sun play a role in climate on the earth

Answer 12

the sun plays a large role in determining the climate on earth, and therefore any changes to the amount of radiant energy emitted by the sun can affect and change our climate

Question 13

what are sunspots

Answer 13

sunspots are huge magnetic storms that occur on the suns surface that cause its magnetic field to break, generating solar storms and thus greater expulsion of radiation from the suns surface

Question 14

what does increased sunspots mean

Answer 14

the extra radiation is sent into the universe, and if directed towards us, can affect the amount of insolation reaching earth

the increase in the number of sunspots that is occurring on the surface of the sun creates greater amounts of solar activity and storms, therefore increasing the suns energy output.

Question 15

describe the suns energy output

Answer 15

the suns energy output has not fluctuated by more than 0.1 to 0.2 per cent in human history, which translates to fluctuations in earths global temperature of roughly 0.1 to 25 per cent of its current warming