TfL has a tool that lets you map travel times to anywhere in London, and it is brilliant

This one shows travel times to Soho. Image: TfL/WebCAT/Google Maps.

“We use WebCAT to provide information on London's transport system to the professional planning community,” explains a rather unpromising page on Transport for London's website. “This connectivity assessment toolkit allows planners to measure public transport access levels (PTAL) and to produce travel time reports.”

I mean, no, that's not exactly doing it for us either, to be honest. You know the voice Steve Coogan uses in The Day Today, when he's a swimming pool supervisor? (“In 1975, no one died. In 1976, no one died...”) That's the voice we're imagining that last sentence in. Try reading it again, but this time, imagine him saying it. In that voice. All nasal and stuff. See?

Anyway. The reason we mention all this is that checking PTAL values and creating time travel maps is just about the most fun thing we’ve seen in weeks.

Let's start by translating this blurb into English. WebCAT stands for “web-based connectivity assement toolkit”. It allows planners to look at maps of particular locations anywhere in London, and see how well connected they are to public transport – something that’s vital, if you're planning new homes or offices.

To do that, it uses two related measures. One is the Public Transport Access Level, or PTAL. That ranks locations on a nine-point scale based on how well connected they are. The best connected places, where you have a choice of high frequency train services and buses, are rated 6b; the worst, where you really might as well walk, are zero. (There are nine points on the scale because values 1 and 6 are both split into two.)

The result of this ranking is this brilliant map:

On the TfL site, you can zoom right into that, and check the transport accessibility of an area as small as 100m square.


That, though, is a fairly blunt instrument. Central Croydon gets a high ranking because it has lots of trains and buses. But it's clearly a bit much to say it's “more convenient” than, say, the Bermondsey riverside, which has a much lower ranking, but from which many people would be able to walk to work.

In other words, PTAL shows where there are good transport links, but it doesn’t show where there are links to.

So, WebCAT also provides another tool: travel time mapping, which does exactly what it says on the tin. It can show you travel times from any point in London as they were in 2011; or you can look into the future, to see how they'll have changed by 2021 or 2031. You can also throw other variables into the mix: time of day, for example, or using step-free modes of transport only.

Using these maps (isochrone maps, to give them the technical name), you can instantly see that CityMetric Towers in London's fashionable Farringdon is – we don’t like to brag – pretty well connected. This map shows average travel times to and from the office in the afternoon rush hour:

Here's travel times from Canary Wharf in the morning rush hour. Unsurprisingly, it's quite well connected to the eastern suburbs, but a pain in the backside to get to or from the west:

That'll change a bit thanks to Crossrail and other initiatives, though. Here's the same map, for 2031. See how the yellow has spread:

Since the Guardian's Alex Hern was nice enough to point us towards this thing, here's a map showing how long it’ll take him to get from his office to everywhere else in London these days:

Our happy hour with WebCAT has taught us one lesson above all others: whatever you do, don't live in the Bromley village of Downe.

All in all, this is really, really cool. Go play.

 
 
 
 

The IPPC report on the melting ice caps makes for terrifying reading

A Greeland iceberg, 2007. Image: Getty.

Earlier this year, the Intergovernmental Panel on Climate Change (IPCC) – the UN body responsible for communicating the science of climate breakdown – released its long-awaited Special Report on the Ocean and Cryosphere in a Changing Climate.

Based on almost 7,000 peer-reviewed research articles, the report is a cutting-edge crash course in how human-caused climate breakdown is changing our ice and oceans and what it means for humanity and the living planet. In a nutshell, the news isn’t good.

Cryosphere in decline

Most of us rarely come into contact with the cryosphere, but it is a critical part of our climate system. The term refers to the frozen parts of our planet – the great ice sheets of Greenland and Antarctica, the icebergs that break off and drift in the oceans, the glaciers on our high mountain ranges, our winter snow, the ice on lakes and the polar oceans, and the frozen ground in much of the Arctic landscape called permafrost.

The cryosphere is shrinking. Snow cover is reducing, glaciers and ice sheets are melting and permafrost is thawing. We’ve known this for most of my 25-year career, but the report highlights that melting is accelerating, with potentially disastrous consequences for humanity and marine and high mountain ecosystems.

At the moment, we’re on track to lose more than half of all the permafrost by the end of the century. Thousands of roads and buildings sit on this frozen soil – and their foundations are slowly transitioning to mud. Permafrost also stores almost twice the amount of carbon as is present in the atmosphere. While increased plant growth may be able to offset some of the release of carbon from newly thawed soils, much will be released to the atmosphere, significantly accelerating the pace of global heating.

Sea ice is declining rapidly, and an ice-free Arctic ocean will become a regular summer occurrence as things stand. Indigenous peoples who live in the Arctic are already having to change how they hunt and travel, and some coastal communities are already planning for relocation. Populations of seals, walruses, polar bears, whales and other mammals and sea birds who depend on the ice may crash if sea ice is regularly absent. And as water in its bright-white solid form is much more effective at reflecting heat from the sun, its rapid loss is also accelerating global heating.

Glaciers are also melting. If emissions continue on their current trajectory, smaller glaciers will shrink by more than 80 per cent by the end of the century. This retreat will place increasing strain on the hundreds of millions of people globally who rely on glaciers for water, agriculture, and power. Dangerous landslides, avalanches, rockfalls and floods will become increasingly normal in mountain areas.


Rising oceans, rising problems

All this melting ice means that sea levels are rising. While seas rose globally by around 15cm during the 20th century, they’re now rising more than twice as fast –- and this rate is accelerating.

Thanks to research from myself and others, we now better understand how Antarctica and Greenland’s ice sheets interact with the oceans. As a result, the latest report has upgraded its long-term estimates for how much sea level is expected to rise. Uncertainties still remain, but we’re headed for a rise of between 60 and 110cm by 2100.

Of course, sea level isn’t static. Intense rainfall and cyclones – themselves exacerbated by climate breakdown – can cause water to surge metres above the normal level. The IPCC’s report is very clear: these extreme storm surges we used to expect once per century will now be expected every year by mid-century. In addition to rapidly curbing emissions, we must invest millions to protect at-risk coastal and low-lying areas from flooding and loss of life.

Ocean ecosystems

Up to now, the ocean has taken up more than 90 per cent of the excess heat in the global climate system. Warming to date has already reduced the mixing between water layers and, as a consequence, has reduced the supply of oxygen and nutrients for marine life. By 2100 the ocean will take up five to seven times more heat than it has done in the past 50 years if we don’t change our emissions trajectory. Marine heatwaves are also projected to be more intense, last longer and occur 50 times more often. To top it off, the ocean is becoming more acidic as it continues to absorb a proportion of the carbon dioxide we emit.

Collectively, these pressures place marine life across the globe under unprecedented threat. Some species may move to new waters, but others less able to adapt will decline or even die out. This could cause major problems for communities that depend on local seafood. As it stands, coral reefs – beautiful ecosystems that support thousands of species – will be nearly totally wiped out by the end of the century.

Between the lines

While the document makes some striking statements, it is actually relatively conservative with its conclusions – perhaps because it had to be approved by the 195 nations that ratify the IPCC’s reports. Right now, I would expect that sea level rise and ice melt will occur faster than the report predicts. Ten years ago, I might have said the opposite. But the latest science is painting an increasingly grave picture for the future of our oceans and cryosphere – particularly if we carry on with “business as usual”.

The difference between 1.5°C and 2°C of heating is especially important for the icy poles, which warm much faster than the global average. At 1.5°C of warming, the probability of an ice-free September in the Arctic ocean is one in 100. But at 2°C, we’d expect to see this happening about one-third of the time. Rising sea levels, ocean warming and acidification, melting glaciers, and permafrost also will also happen faster – and with it, the risks to humanity and the living planet increase. It’s up to us and the leaders we choose to stem the rising tide of climate and ecological breakdown.

Mark Brandon, Professor of Polar Oceanography, The Open University.

This article is republished from The Conversation under a Creative Commons license. Read the original article.