Science of Climate Change Flashcards
how does climate differ from the weather?
Climate = idea of average weather
- measurements of the mean and variability of relevant qualities of certain variables eg. temp over months to thousands of years - classically 30 yrs
climate is what you expect weather is what you get!
Weather - shorter time period - what you get
How are weather and cliamte observations made
staelites
commerical airlines
weather balloons
ships
bouys
weather stations
how is the general data coverage of the world in terms of climate and weather
inhomogenous
agg on land rather than sea
give me some reasons for why there is uncertainties in the global mean temperature record
choice of data sources
spatial interpreation
changes in measurement techniques over time
measurement error
Why would a regional warming be less clear than global warming on the temperature record
- more interannual variability in regional central England team record compared with global temp
= signal of global warming is harder to detect because of the noise (random variability) is large - have to average over a larger spatial or temporal scale to average out the weather
Describe some physical phenomena that indicate the climate is changing and what do they say?
global mean temperature - variability on annual to decadal scales
- warming nearly everywhere but some regions are warming faster than others
shrinking crysophere - ice sheets, glaciers and sea ice–> oceans absorb extra heat content and mean sea level rises
Co2 increases also cause the acidiciation of oceans - pH DECREASES
How are we sure that the climate is changing due to human influences?
Theory - there is more CO2 in the atmosphere than ever therefore having a stronger greenhouse gas effect
Models - climate models cannot reproduce the current trends unless there is the inclusion of human made GHG emissions - every climate model producers warming when Co2 increases
There has always been extreme weather what has changed
there is a trend towards more hot extremes and fewer cold extremes towards the end of the 20th cent
this doesn’t prove human influence however we are generally confident that human influence extreme heat
What do we know about precipitation extremes?
less confident in estimations and even less confident about precipitation and storms
these variables have larger variability and changes are not always spatially uniform
Joseph Fourier theorised what about the atmosphere?
that the earths atmosphere kept the earth warmer > if there was no atmosphere
basically the greenhouse effect
John Tyndall identified what greenhouse gases?
Co2, water vapour and methane as greenhouse gases
noted that changes in these gases could cause climate change
Svante August Arrhenius thought what
first to predict that emissions of Co2 would cause global warming
calculated a 5-6oc charming per doubling of Co2
Who was your gal Eunice Newton Foote
identified the role fo Co2 as a GHG
What is signficant about the Keeling curve
it shows the amount of atmospheric co2 concentration and how they have changed since the late 50s - maintained ever since - required an understanding of how the ocean acts as a buffer for CO2 and how extra Co2 in the atmosphere has an impact.
