Kategoriarkiv: Earth


During the Olympics in Beijing there have been quite a lot of discussion about the bad air in Beijing. And as I have myself visited Beijing several times I can say that the pollution is something that you definitely notice and can be quite bad at times. It’s quite boring when you do not see the blue sky for many days in a row. But it’s also shifting a lot, suddenly the air is very clear.

By the way here is an image of me in front of the olympic stadium which was under construction about one year ago:

There are official measuremnts of the air quality in Beijing that can be seen at MEP, while both BBC and Associated Press are making their own measurements.

The figures differs a bit and of course there can be big local variations, but until now AP has measured an average value of 326 micrograms per cubic meter of PM10 which is the most common measurement for air pollution. You can read more about PM10 at Wikipedia but one reason for importance of this measurement is that it measures particles with a size smaller than 10 micrometers, which is small enough to settle in the lungs and cause health problems. BBC’s values are a little lower with maximum values around 300, also according to BBC the yearly average is around 89. The official government data is around 160 under the olympics so far. Nevertheless it can be interesting to compare these values with other cities and your own local area.

BBC also mentions that the yearly average for London is 21. The most polluted city in the world, Cairo has a yearly average of 169, thats almost double the average of Beijing.

I found an article with numbers from Linköping in Sweden which is not far from where I grew up, there the numbers for the yearly average ranges from 18-26 depending on location in the city. Perhaps the numbers can’t be compared, but just looking at them it seems that London and Linköping is equally polluted, I find that hard to believe but anyway they are far from Beijing. In Sweden the yearly average can not be above 40 without actions being taken.

Looking at the city where I live (Oslo, Norway) one can see that the yearly average is around 25, and the report I looked at actually had data back to the 1970’s and it’s interesting to note that the PM10 values for Oslo are now only a third of what it was then, the average for 1971 for example was 74. In the 1980’s it was around 40-50, in the early 1990’s around 30. The same report also looks at SO2 where the measurements go back to the 1950’s with values around 300-400 micrograms per cubic meter, and in the early 2000’s the values were down at only 4-5 micrograms per cubic meter. NO2 was also down by the way. I was not aware that the air is so much better now (at least when looking at those three pollutants) then a few decades ago, interesting… But I am just looking at some numbers, how much of an improvement this really means I can’t say. Anyway all reports about Oslo and daily measurements can be found at luftkvalitet.info.

Well enough numbers and measurements, I am going to watch some Olympics instead 🙂

Earth Climate

Considering the debate about the global warming there are some curiosities that is interesting to know.

Did you know that if you compare to the historic climate of the earth that we have an unusual amount of ice at the moment? We have permanent ice at both the poles, 10 % of the area of our earth is covered by ice and 75 % of all fresh water is ice. Actually the most common state of our planet has been to have no permanent ice at all. Technically we are currently still in an ice age.

Regarding the discussions about the global warming it not really about the current state of the temperature it’s about the change.

Just like Michael E. Mann comments in this article:

Its not the absolute state as much as the rate of change, which presents the real challenges and threats.

By the way if you have a good idea about how to remove anthropogenic, atmospheric greenhouse gases you can win a price of 25 million dollars at the Virgin Earth Challange. 🙂

Life on Earth

The history of life on Earth is interesting. Consider the following, we compress the entire lifespan of our home planet into 24 hours. The age of the Earth is about 4.6 billion years i.e. 4600 million years, which by the way we have not known about for that long. The current age was calculated approximately during the 1950’s. Most earlier calculations and predictions gave shorter estimates. Using todays estimates of the age of the universe, the Earth has existed for almost exactly 1/3 of the age of the universe.

But back to the life part, life appeared on our planet as early as 04:00 in the morning on the compressed timescale as small microbes, but then it took a really long time before anything new happened. At 20:30 the life on earth still consisted just of microbes. But now the first plants appeared in the oceans, twenty minutes later the jellyfishes and at 21:04 the well known trilobites appears. At 22:00 plants start to grow on land, and at 22:24 there are forests and insects. At approximately 23:00 we can see the dinosaurs which exists for about 45 minutes before the extinction event wiped them out. Humans arrive at 23:58:47 (one minute and 17 seconds before midnight). On this scale the life of a human is about 1 thousand of a second which by comparison is about the the same length as it takes for the flash on your camera to finish.

Our planet is a dangerous place to live on, there have been numerous occations of extinctions when many of the species have died out. Most of theese occations we do not know exactly what happened, but there are some different things that might have happened:

  • Global warming
  • Global cooling
  • Changes in waterlevel
  • Depletion of oxygen in the ocean (Anoxia)
  • Epidemics
  • Huge leaks of methane from the bottom of the ocean
  • Comets and meteors
  • Hypercanes (extreme form of hurricanes)
  • Volcanoes
  • Big Solar flares

And of course there exists other possible theories also.

Five of the extinctions are commony called ”The big five” which includes the events ”End Ordovician”, ”Late devonian”, ”End permian”, ”End Triassic” and ”End cretaceous”.

The biggest one of them all were the ”End Permian” one that happend 251 million years ago, this was before the dinosaurs. A whopping 95 % of all species died out (96% of marine species and 70% of the land species). It took about 6 million years for the life to recover again. In june 2006 there was found a huge meteor crater under the Antarctic ice sheet that might be the cause of this extinction event. The crater diameter is about 480 km (thus twice the size of the crater that have been suggested as the one that killed the dinosaurs). This is not proved of course but it’s one theory.

Big objects from space impacts with the Earth quite frequently, and in the 24 hour day above you would be able to see about three impacts per minute from objects larger than 2km in diameter. And those are big ones. The history of humankind has yet been spared the really big ones, but U.S. Geological Survey in fact estimates that impacts that release as much energy as the atomic bomb dropped over Hiroshima in Japan during the war happens about once every year. In modern history the biggest recorded impact wats the one in Tunguska in Russia 1908, 80 million trees were destroyed, but there was no crater left as the object exploded before it hit the ground.

The other four of the big five extinction events wiped out around 70% of all species.

Another interesting thing to note is that among the 7 biggest extinction events are ”Present day” listed, this is disputed but a survey showed that 70% of asked biologist think this is the fact, and some research points to that 50% of all species might be gone in as little as 100 years or possibly a few hundred years, and this is of course extremely fast.

Some species die and new ones come forth, this seem to be normal throughout the history of life on Earth and we should be happy we are still alive. It has been discovered that the more advanced a species is the faster it seems to die out, we are now pushing the limit of this average lifespan, but perhaps we are intelligent enough to prolong this. But if a big catastrophic event occurs there might be little we can do of course and we might also be stupid enough to destroy ourselves.

Anyway 99.99 % of all species that have ever existed on our planet is no longer with us.

RIP all billions of species!! Hmm I have a feeling that I don’t miss some of them though 🙂