## Friday, February 1, 2013

### The math behind climate change: Part 2What is a "reasonable" span of years to check?

As I stated in yesterday's introduction, it is my hope to create a standard that will be accepted (or at the very least debated) in the climate science community for what constitutes cherry picking and what does not. The place to start is to define what is a reasonable span of years to check for change in climate.

This is a graph of the average temperatures in Spring in Greenland from 1955 through 2011. Spring in Greenland is one of those regions over time where the data is by no means overwhelming in terms of warming. It's easy to see a peak in the mid 1970s, a cooling trend until the early 1990s and a general warming trend since. 2010 was the warmest Spring in over 50 years, but 2011 sunk to the coldest Spring this century.

What gives?

We need to remember that weather is not climate. The peak in 2010 does not prove the planet is getting warmer any more than the plummet in 2011 proves it's all bunk.

I propose that certain start dates and end dates should be accepted by people discussing the data as fair cycles. Showing my California bias, I want to look at the pattern of years that are counted as El Niño or La Niña years, which means warmer or cooler than average respectively over much of the Pacific and Indian Oceans, a substantial percentage of the earth's surface. There are other such patterns around the world and using the same method I propose here for Niño/Niña would be reasonable in those areas. (For example, since Greenland is in the North Atlantic far from the Pacific or Indian Oceans, using Niño/Niña cycles might be less constructive than using a cycle in the oceans closer to the island.)

Here is the list of El Niño and La Niña* years since 1950.

La Niña   El Niño
1950
1952
1954

1955
1956

1958
1964

1966
1969

1970
1973
1975

1977
1983
1987

1988
1992
1995
1997

1998
2002
2006

2007
2009
2010
2011

My proposal is this. To look at a set of years, it is acceptable to start in an El Niño year, but it should be at the beginning of a clump of El Niño years.  The end of a pattern should be the last year of a clump of El Niño years that is at least two El Niño clumps away, which is to say Niño/Niña/Niño/Niña/Niño.

Likewise, a pattern could start in the first year of a La Niña clump, then pass through Niña/Niño/Niña/Niño/Niña. It is also acceptable to look at longer patterns, but always starting at the beginning of one sort of clump and ending at the last year of the same sort of clump.

Here is the list of the acceptable year ranges starting with the La Niña years, written in blue.

1950 to 1964
1950 to 1975
1950 to 1988
1950 to 1995
1950 to 1998
1950 to 2007

1955 to 1975
1955 to 1988
1955 to 1995
1955 to 1998
1955 to 2007

1964 to 1988
1964 to 1995
1964 to 1998
1964 to 2007
1970 to 1995
1970 to 1998
1970 to 2007

1988 to 19981988 to 2007

1995 to 2007
Here is the list of the acceptable year ranges starting with the El Niño years, written in red.

1952 to 1969
1952 to 1987
1952 to 1992
1952 to 1997
1952 to 2006
1952 to 2009

1958 to 1987
1958 to 1992
1958 to 1997
1958 to 2006
1958 to 2009

1966 to 1992
1966 to 1997
1966 to 2006
1966 to 2009

1977 to 1997
1977 to 2006
1977 to 2009

1992 to 2006
1992 to 2009

1997 to 2009

You will notice that no data pattern allows us to include information past 2009 yet, because we don't have an El Niño year to end the current La Niña clump. This may well go against the grain of people on both sides of climate debate who want to use latest data to prove their point.

My fond but forlorn hope is that these people will get over it.

If it is real, climate change is exactly the kind of problem humans are worst at solving, slow moving catastrophes that require action now to stop disasters in the future. Politically, the climate debate is mostly the left saying "Act now!" and the right saying "Bite me!" When it comes to entitlements and the budget deficit, the political sides are reversed. Neither problem is truly being addressed today.

It's not impossible to address long term problems. The Dutch, who understand their seaside country is largely under sea level, have built a remarkable set of levees and dikes. Americans did a less convincing job of protecting New Orleans. When the ozone layer was showing remarkable change, the aerosol industry was convinced into changing what they used as propellant. Climate data has done nearly nothing so far to change either the petroleum industry or its addicted consumers to change their ways.

How to start effective change if necessary is not the current goal of this series of blog posts. This is just to start a framework that has everyone discussing climate using the same benchmarks.

As I wrote on my Facebook page this morning, I was thinking about bringing peace to the Middle East, but this looked more challenging and more mathematically rich.

Tomorrow: turning lots of data into quarterly average data.

*Note: El Niño was named first and the opposite effect started out named La Niña, but some objected to the sex-based insinuation "boys are hot and girls are cold". Some wanted to call the opposite trend El Viejo, which would translate to the age-based statement "boys are warm and old men are cold". As a no longer young man, I find El Viejo more accurate metaphorically than La Niña, but the names appear to be pretty well stuck by now, more the pity.