Krugman got me thinking…

Paul Krugman posted a blog entry about the tired old canard that life expectancy was much lower when Social Security was implemented, so increasing life expectancy is bankrupting the system.   Of course, the drastic increase in life expectancy, from 68 to 78 is improvements in saving the lives of children.  This gets at a fundamental aspect of life expectancy calculation.

When we talk about life expectancy, we’re usually referring to life expectancy at birth.  There are many reasons we use this statistic and many reasons it’s not a reliable indicator for people of various ages.  Prior to the development of modern, evidence-based medicine, mortality rates during various stages of life were quite high.  All deaths at all ages are incorporated into the calculation of life expectancy at birth.  In a society where there is no modern medicine, many infants don’t survive their first year.  If a child survives that year, their life expectancy increases because we’re calculating the statistic from a different sample, namely all of the other people who lived at least one year.  Similarly, childhood diseases kill.  A child who survives to puberty has a greater life expectancy from that point on for the same reason he or she gained increased life expectancy for surviving the first year of life.  The kids who didn’t make it (and there are a lot of them) are no longer included in the calculation.  Here’s where it gets really interesting.  After puberty males and females are subject to different effects on life expectancy.

Females have their fertile years ahead.  Before modern gynecological and obstetric care, there was a huge risk to having children.  Child birth is dangerous, and many women died (still do in developing countries) during the process.  Making it through their childbearing years into menopause again increased the life expectancy of women.  Males don’t suffer the high death rate caused by child birth, but they are the ones who have historically fought in wars.  Surviving long enough to no longer be considered for military service increases the life expectancy of men.

As a case study, let’s look at Sierra Leone.  Life expectancy at birth is 39 for males and 42 for females.  This is among the lowest in the world, and one might assume that the population of the country is quite young since people don’t live very long there.  However, the statistic is dramatically skewed by two big things.  Sierra Leone has the highest infant mortality rates and under five mortality rates in the world, and one of the highest maternal mortality ratios (see pg. 26).  Further, Sierra Leone was embroiled in a civil war for most of the 1990s.  These factors mean that mortality rates are very high during life, however, there are people who are over 65 in Sierra Leone.  Just over three percent of the population is 65 or older, but they are there.

So, if you make it to your middle years, there’s a good chance you’ll live to be 65 or so.  That’s why even in countries where the life expectancy is reported as very low, there are elderly people roaming about.  They’re the ones who survived the various dangerous stages and therefore will probably live to be “old”.

More ice problems

new ice island four times the size of Manhattan has broken off of the Petermann Glacier in Greenland.  The Petermann Glacier is on the northwestern end of Greenland, and the new ice island will eventually drift out to the Atlantic Ocean by way of Baffin Bay.  Wikipedia has a satellite photo from NASA of the glacier.

Beautiful isn't it?

One of the concerns associated with global warming is the release of freshwater into the norther Atlantic as sea ice and glaciers from the Arctic melt.  There is real concern that this deluge of fresh water may upset the Atlantic Meridional Overturning Circulation.  If the movement of warm water north and cold water south is disrupted, winters could become much more severe for people living in the northern latitudes of Europe and the USA whose climates are moderated by the ocean and its transportation of equatorial warmth north.

As the signs continue to mount that global warming is a dangerous reality, some people continue to deny that there is anything wrong.  I classify the denialists into three basic types.

1. The people who believe nothing is going on.  This group includes the imbeciles who say such ridiculous things as “It’s cold right now, so global warming can’t be real.”  Among this group are people who lack an understanding of the difference between weather and climate.  In 2009 many places experienced record low temperature maximums (this means the high temperatures were lower than they ever had been).  Denialists of the first kind took this as evidence that global warming, which, of course, should be called climate change, isn’t happening.  I wonder if these people are related to the “microevolution happens, but macroevolution can’t” type of creationist.  Other manifestations of this kind of denial include references to scientists who thought we would be entering an ice age, and questioning the credibility of climate scientists.  A favorite tactic of the leaders in this group is to call Al Gore fat.  This group of people needs more information.  Also, they’re idiots (and probably Republicans).

2. The people who believe something is going on, but it is not caused by humans nor can it be mitigated by humans.  These people are the kind to say it’s all solar flares or natural changes in the climate.  They cannot read a simple graph (and probably call themselves Independents while voting Republican).

3. The people who believe that global warming is real, caused by human activity, and could be mitigated through changes in human behaviour, but who cynically manipulate the public to oppose any regulations that may hurt the profitability of their businesses.  These people are known as corporate executives of fossil fuel companies.  They are jackasses (and also Republicans).

Update on the ISS cooling system

According to Spaceflight Now a leak in one of the ammonia lines has delayed repair of the broken cooling loop.  The final repairs will be done on Wednesday.

Job losses continue

The Guardian reports that the US lost another 131,000 jobs in July.  Much of it can be attributed to the Census winding down, and laying-off employees, but June estimates have been revised to 221,000 from 125,000.  Paul Krugman suggests that politicians may be busy redefining what it means to have a good economy.  Dr. Krugman has been deeply critical of current economic policies around the world in his blog and his column.  Of particular concern is the move by many countries to “tighten their belts” and cut spending.  It’s truly astonishing that so many people around the world have forgotten the Great Depression and written Keynesian economics off.  Increasing government spending is the only feasible method of stimulating the economy at this point.  The Fed is already up against the zero bound, so there’s not much that can be done by way of monetary policy to help the economy.  We desperately need big spending on public works.  Hell, it’s obvious that the US has crumbling infrastructure in need of major overhaul.  Why not fix our stuff and stimulate the economy at the same time?

There are other economic issues here, such as the out-sourcing of US manufacturing, limiting the effects of economic stimulus, but that’s another issue to be tackled after we stabilize the economy.

Book Review: Parable of the Sower

I’ve recently finished reading Parable of the Sower by Octavia Butler.  Set in the near future (2024-2027 C.E.), the premise of the book hinges on the collapse of society in the face of drought in California caused by global warming.  We learn about the world of Parable of the Sower through the journal of Lauren Olamina, the 15 year old protagonist.  Lauren lives in a walled neighborhood in Robledo, California, a suburb of Los Angeles.

Octavia Butler addresses many issues that may arise with a collapsing society.  Rampant inflation, along with water shortages has made the bare necessities of life extremely expensive.  High unemployment has caused the ranks of the poor to swell tremendously, and poverty stricken people live in the streets.  Food, particularly dairy and meat, is very expensive, so everyone who has space grows as much as they can.  Dealing drugs can provide huge profits, but is extremely dangerous.   Even though they are middle-class, the Olamina family struggles with funding their basic necessities, but they are lucky because Lauren’s father has a good job at the university.  As an example of how much society has changed, Lauren’s middle-class family is unusual because her step-mother makes sure that all of the children have two pairs of shoes.  Unlike other neighborhood kids, Lauren and her brothers wear shoes when they are outside in their own neighborhood.

As the divide between rich and poor becomes larger, and the middle class smaller with a more precarious existence, company towns spring up.  One California town sells itself to a corporation promising jobs, food, housing, and most importantly, water from a new desalination plant.  Both Lauren and her father see the parallels to 19th century mill towns where employees are paid in company scrip and become indebted to their employers.  Lauren sees this as a path to slavery.  Later in the novel, Lauren meets two former slaves who reveal that her predictions of employees working off their “debts” to the company under the conditions of slavery have come true.

Outside of Lauren’s walled community a drug that inspires people to start fires sweeps the USA.  People who take this drug (pyro) paint their faces and burn buildings during the night.  Some characters mention that the “paints,” as the drug addicts are called, burn the property of the rich as a means of getting revenge for the poor and opening the walled communities to desperate scavengers, but other characters aren’t so willing to accept that the drug-users have motives beyond the joy of watching something burn.  Since paints also engage in many other violent behaviors such as rape and murder, the reader has reason to doubt the supposed political motive behind the burnings, too.  Eventually, as pyro spreads from the East Coast to California, Lauren’s community is attacked and burned, killing most of the people who lived there.  Lauren sets off with two other survivors for Oregon and the promise of a better life.

I won’t ruin the rest of the novel by giving away the ending.  There are a few things I found interesting, though.

When she is trying to explain to a friend how humanity must change if it wants to survive, and that the adults are holding them back, Lauren mentions the societal upheaval and change following the Black Death in Europe.  Though the adults in her community keep faith that things will be okay again, Lauren realizes the old ways are dying.  After the Black Death swept Europe, the structure of feudal society began to change.  With so many in positions of power succumbing to the disease, new opportunities opened for the lower class.

Dogs are not pets in the world of Parable of the Sower.  They are deadly predators.  Only the rich can afford the amount of meat dogs consume every day.  Several times throughout the novel, the protagonist faces feral dogs threaten her life.  For reference, wolves need to eat around 7 pounds of food per day.  In a world where breeding rabbits for food in your backyard is a profitable enterprise, feeding that much meat to an animal would be unthinkable.

Butler wrote Parable of the Sower in 1993, so I am unsure of the predictions climate scientists were making regarding precipitation changes in California at the time.  In Lauren’s world, rain is so rare that she measures the time between downpours in years not days or months.  The scarcity of water drives much of the social change and conflict of the novel.  Current projections actually indicate dramatically increased rainfall in California, (warning, pdf) particularly the southern half.

Finally, Lauren is African-American (as was the author).  Race is not central to the story, but it does have significant impacts on the plot at times, as does Lauren’s gender.  For instance, mixed race couples face increased risk for attack on the road, making Lauren careful in choosing her companions during her journey.

I may post more on this, but these are my first thoughts after reading the book.

xkcd rocks!

I love today’s xkcd!
go to the original for the alt text

Touble on the International Space Station

There is a problem with the cooling system on the International Space Station.  According to the BBC, the station’s cooling systems operate using two ammonia-fed cooling loops.  One of these shut down last night.  The remaining cooling loop has no back-up and repairs to the faulty cooling loop will require two spacewalks

Living in space is dangerous.  Thermal control on-board the ISS (and other space vehicles) is absolutely essential.  Without the temperature regulating atmosphere to protect them, people on board the ISS would be exposed to deadly temperature extremes.

Without thermal controls, temperatures on the ISS’s Sun-facing side can soar to 121C (250F), plunging to minus 157C (-250F) on the dark side, Nasa says.