Liam Taylor

Liam Taylor

Lecturer at Leeds University researching the impacts of climate change on our world

Course producer for University of Exeter Global Systems Institute


Location Leeds, UK


  • Great summary :)

  • Absolutely right. The atmosphere is just the collection of gases that are within the gravitational pull of the Earth. Ones that aren't, are blown away into Space :)

  • Hi Emily - Great answers! Thanks for posting the links to your research :)

  • Let's imagine we've got 2 mugs of water. The first mug contains hot water from a tap, the second mug contains boiling water.

    If we hold our hands above both, we can feel heat energy coming off them. But the mug that contains boiling water is radiating more heat energy than the mug containing hot water.

    Hotter things radiate more heat energy, and thus...

  • Really nice summary! :-)

  • Water does get quite complicated. When we give albedo values, it's generally averaged out over a very very large area - so open ocean has an albedo of around 0.08-0.10 (reflecting 8-10% of solar radiation). Shallower water bodies can have a higher albedo, and yes, there are physical properties of that can affect it.

    Ocean though is ~10%. If you find the 30%...

  • Yes, absolutely, and different gases stay in the atmosphere for different amounts of times. What drives the mixing is atmospheric circulation patterns. These are driven by how different parts of the Earth warm up, the way the Earth spins, where the land on Earth is etc. This website should give a good overview :-)...

  • Yes, it does.

  • Welcome to all of our learners! And what a good day for this course to begin - Earth Day. On behalf of the team, we wish you all the very best for the course, please post your questions in the comment section :-)

  • Thanks for joining us Elisa! :-)

  • Hi Charlotte. The advice I've been given (I don't work for the University of Exeter) is to register your interest if you're keen on any of the postgraduate options. They are finalising the full details of the programme, but haven't yet said whether its online / on-campus. Sorry I can't be more help!...

  • Good question! I hadn't thought of this before! With a bit of googling, this has only posed more questions!

    The amount of water (ice) in permafrost massively depends on the ground material. Ice can make up anywhere between 10-90% of the volume of the material. But we only know what the content is by drilling into it... and that requires significant time and...

  • Hi Beatriz - Apologies but we cannot open this video for download because it does not belong to us (Swansea University very kindly let us show it on the course). You can also find the same video on YouTube -

  • Hi Anthony - Check out this video of a similar calving event. It goes on a bit, so skip to about 3 minutes 50 where they place Manhattan over the ice to show you the absolutely phenomenal amount of ice that's lost in these events.

  • Hi Mike,

    Fantastic question. The large tongue at the front of Jakobshavn Isbrae (the glacier we looked at in the video) retreated because of warm waters in the fjord, melting the glacier from beneath. The water temperature has increased by over 1°C since the 1980s.

    Jakobshavn Isbrae massively accelerated its retreat rate from 1998 due to a very warm...

  • Good question! Particularly as there are bits of 'East' Antarctica that are actually to the West of the pole!

    The convention comes from the mountain range that runs slightly to the west of the south pole (The Transantarctic Mountains). These mountains pretty nicely split Antarctica into two seperate ice sheets - the ice sheet that is to the East and the ice...

  • I can very strongly recommend Chasing Ice and Chasing Coral (for the later parts of this week). Both are on Netflix! I showed a clip from chasing coral to a class of 13-14 year olds and had quite a few in tears.

  • Yes, definitely! And there has been evidence that this is the case. This article (though written for 'entertainment', is scientifically accurate) covers quite nicely the issue.

  • @MargaretJohnson Yes, these are called ice stupas! They are created artificially during the winter and when water is plentiful, then they act as a store for water, melting during the summer when water is scarce again.

  • Very good points Angela!

    There are a few mountain glaciers in temperature regions that do calve - into lakes at the front of their terminus. These lakes are very popular for drinking water - particularly in places like Nepal and Peru. If large calving events occur, the lake can overspill and cause flooding downstream - in very very extreme circumstances.

  • Hi Paula,

    Great questions. Yes, regional pressure systems do cause an increase in melt. Arctic sea-ice melts more under high-pressure systems, for example. Current climate modelling isn't yet good enough to say whether we'll get more of these systems in the future though.

    It's likely we'll see something similar again. Remember, the 2012 event was a...

  • Hi Mikko,

    Apologies for missing these questions!

    Very difficult to quantify our mitigated carbon emissions! There are so many things we don't know - for example the strength of the terrestrial biosphere in absorbing carbon emissions. About half of the carbon emissions we release each year enter the atmosphere - which suggests that the other half is being...

  • Interesting questions! Yes, in the same way that we can use dead trees to reconstruct the past, because the tree rings don't degrade, dead corals can also be used. Just as long as they remain in a good condition after death.

    There's always more to learn. Just today, the British Antarctic Survey announced they'd drilled to the bed of the Antarctic ice sheet...

  • Sort of! They cause lower temperatures on the short-term, exactly as Trish has said. The dust and some aerosol particles (like sulfur dioxide) that they eject into the atmosphere reflects solar radiation, causing short-term cooling. But these drop out of the atmosphere in months or just a few years.

    However, the carbon dioxide they release stays in the...

  • Out of pure curiosity, I've found that the oldest living tree is currently about 5000 years old! Very ethically dubious if we start coring these ancient ancient trees though!

  • Hi Graeme - It's the sun that's expanding. The Earth more or less hasn't changed in size since it was formed.

  • Ah, very glad to hear it! :-)

  • Great question Nick. In short.... we're not quite sure. It's likely a combination of a number of things - including lower solar activity, the Earth being tilted away from the Sun or even a supervolcano eruption that blocked out solar radiation for a while.

    However, what is likely to have been the main reason, is that the continents were all bunched up...

  • Yes! One source I've found suggests that the Earth has grown by about 14% since Earth first formed. We're in a fairly stable phase at the moment (called the 'main sequence'), where it doesn't grow much or change in brightness too rapidly. The brightness of the Sun was about 70% of what it is now when Earth first formed. Early Earth was only warm because of a...

  • Hi Sue - Is there anything in particular you'd like some help with? Please do ask questions if ever your stuck - that's what I'm here for :-)

  • Yes! We've observed many more of these lakes on top of the ice, growing in number and extent. Using satellites, we can also watch these enormous lakes rapidly drain over a matter of days. All of that water either goes straight into the glacier, warming it from the inside out, or to the bed, lubricating flow.

  • My bad! I rewrote this article fresh for this run of the course - forgot to run it through a spell check... oops!

  • Hi Nick. Interesting questions.

    1) In short, we're still not sure. Likely that just the rest of the natural system 'caught up'. Ocean sediment cores show increased deposition, and more biological activity, which will have helped cause an abrupt end and recovery.

    2) Unfortunately, not quite. Venus is an extreme example, showing that there aren't maximum...

  • Hi Peter - You're right, these are likely Holocene peat bogs. This landscape is called 'thermokarst' and is a visual indication of permafrost thaw across a large area. (More in Week 3 on that!). Permafrost contains the methane hydrates that likely caused the PETM event. I agree though it looks a wee bit out of place here - I've added a caption to the image to...

  • Hi @ZulqarnainAlam - What a good idea! I have added this as an activity at the end of Week 4 (step 4.12) - I'm very interested too. Thanks for this idea :-)

  • Thanks for the links :)

  • Hi everyone. I've added the word cloud from the first activity to this article, where we asked you to write your three words about what climate change means to you. Do any of the words surprise you? Is it what you expected?

  • Thank-you to everyone for engaging in this activity! You can find the first word cloud of your thoughts in Step 12 at the end of Week 1 :-)

  • I've seen a few different ways this is described. Next week, we tend to describe 3 types of climate change. Anthropogenic climate change (that's the contribution of humans to changes), Natural climate change (no humans involved) and then use climate change as an umbrella to describe all changes that are observed.

  • Stick with us Angela! Next week is all about putting climate change in the context of geological time and natural climate changes, and in Week 4 we look at the future, including some of these hypothetical situations.

  • Thanks Areum! Please let me know if you have any questions that I can help you with :-)

  • Thanks for the feedback! :-)

  • Hi @MatthewShort - Thanks for all of your contributions this week, I've loved reading them all. I don't want to overwhelm you at all, but just wanted to point you in the direction of our second course which is beginning