Based on his name and the picture in the article, I assume the author is Dutch. We don’t have the distinction between underpasses and tunnels in our language and just call everything ‘tunnel’. It may have to do with the country being so flat that there are no mountains to tunnel through.
I can only think of a single real bicycle/pedestrian tunnel, which is the Maastunnel in Rotterdam. Incidentally it is also one of the oldest tunnels in the country. It was recently renovated and is actually really pleasant to cycle through, because motorised traffic uses a separate tunnel tube.
As for turns in underpasses, at complex junctions or infrastructural elements it may be tempting to just make a small bend so that the underpass is cheaper to build or easier to fit in to the environment. Take these crossroads for example: https://goo.gl/maps/21Yqj89WwyiiuZfD9. If you look closely you will see a bicycle tunnel going underneath from the southwest to the northeast. This important connection for the residents southwest of the shopping center is relatively long and has a slight bend. This makes it feel dark and unsafe to the people who use it.
A better design can be found at this roundabout: https://goo.gl/maps/TXuFjXj85huufc7m6. Because the middle section is open, all of the individual underpasses are short and there is a lot of daylight, making cycling there safer and more pleasant.
I think it has to do with design. They wanted to make the two top rows have the same amount of lights. Using 6 would mean one row of 6 lights and one of 4. 5^2 is the smallest square that provides enough values to fit 24 hours.
When a tree dies that CO2 will mostly just be released into the air again. Planting trees is a measure to slow the immediate effects of fossil fuel usage, but not a long term solution. At some point you’ll run out of space for new trees.
It’s like fixing a leaky pipe by adding sponges. Sure, they’ll soak up the water and are cheap, but eventually you will run out of space for new sponges and have to pay for a plumber.
While this is a good development, hydrogen based planes would not be climate neutral. Unfortunately a large and often overlooked part of planes’ climate impact stems not from their carbon emissions but from the water vapor they produce [1]. Contrails reflect heat and thereby contribute to global warming. If we want planes to actually be harmless to the climate, we should probably be looking at electric planes.
I read that AC installation companies have been getting a lot of business in the past few weeks, and anecdotally I've heard from local businesses looking to install it as well. So I'd say yes, it'll definitely become more common.
We generate a lot of heat, but so does the sun by shining on half of the earth's surface. That should not be a problem however, since it goes back into space in the form of infrared beams. The natural greenhouse effect obstructs just enough of those beams to keep our planet at a stable temperature that life has had plenty of time to adjust to. Now that the greenhouse effect has been artificially enhanced by adding lots of greenhouse gases to the atmosphere, more infrared beams (from the sun, but probably also some from human activity) are kept in the atmosphere and so it warms. So ultimately, the sun is just vastly more powerful than human activity, and any excess heat would be emitted into space if it weren't for the artificially raised greenhouse gas concentrations in the atmosphere.
Well, there are six intercity trains per direction each hour to Amsterdam Central, four to Amsterdam South (will be upped to six in a few years), and up to four commuting services. So you could even say there’s a train every 4.3 minutes.
With just 16km, this is not by any stretch going to be the world's second-longest tunnel, just the world's second-longest road tunnel. The longest tunnels are rail tunnels, which measure up to 57km (Gotthard base tunnel), and if you count subway tunnels the longest is Guangzhou metro line 3 with 60km. (https://en.wikipedia.org/wiki/List_of_long_tunnels_by_type#U...)
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I can only think of a single real bicycle/pedestrian tunnel, which is the Maastunnel in Rotterdam. Incidentally it is also one of the oldest tunnels in the country. It was recently renovated and is actually really pleasant to cycle through, because motorised traffic uses a separate tunnel tube.
As for turns in underpasses, at complex junctions or infrastructural elements it may be tempting to just make a small bend so that the underpass is cheaper to build or easier to fit in to the environment. Take these crossroads for example: https://goo.gl/maps/21Yqj89WwyiiuZfD9. If you look closely you will see a bicycle tunnel going underneath from the southwest to the northeast. This important connection for the residents southwest of the shopping center is relatively long and has a slight bend. This makes it feel dark and unsafe to the people who use it.
A better design can be found at this roundabout: https://goo.gl/maps/TXuFjXj85huufc7m6. Because the middle section is open, all of the individual underpasses are short and there is a lot of daylight, making cycling there safer and more pleasant.