Climate change has suddenly become a hot research topic in Bolivia (1). The glaciers in the highlands are melting, the lowlands are flooded, and the government has declared a state of national emergency due to natural disasters. It is a good time to ask how climate change might be affecting the poor Bolivians.
But first let’s check exactly what climate changes we are talking about.
The National Meteorological Service (www.senamhi.gob.bo) provides useful data for 33 different stations across Bolivia. They provide daily minimum and maximum temperatures since 1/1/2004 until yesterday, as well as historical monthly averages for the 1961-1990 period, which can be used for comparison. It is therefore relatively simple to calculate daily temperature anomalies for different parts of Bolivia.
The results of such an exercise might surprise you.
Of the 33 Bolivian weather stations, 7 experienced significant warming, 6 experienced no significant change, and 20 experienced significant cooling. Most of the cooling took place in the highlands (-1.5 degrees Celsius in Charaña, -1.2 in Oruro, -0.5 in Potosí, and -0.3 in El Alto, for example), while the lowlands experienced much more modest changes (about -0.2 degrees in most places).
Central La Paz is an atypical place by Bolivian standards, with warming of about 1.4 degrees Celsium in the recent 4-5 years compared to the average for 1961-1990. One might suspect the urban heat effect to be playing a role here, as La Paz is full of concrete and has little vegetation to soften the effect. If any of the readers know exactly where the Central La Paz station is located, I would like to take a look at it.
Some people might be sceptical of these “cooling” results and suggest that the SENAMHI data are bad. Certainly, there are a lot of missing observations. The person responsible for recording temperatures at Potosí airport, for example, doesn’t work weekends, so two-seventh of the observations are missing. Other stations didn’t start recording until 2006.
If we limit ourselves to the 17 stations with most complete data (at least 1100 daily observations since 1/1/2004), we find that 3 stations experienced significant warming, 2 experienced no change, and 12 experienced significant cooling. So, pretty much the same pattern.
If you don’t trust Bolivian data at all, there are also some international data available. The longest series, I could find, is for El Alto for the 1/1/1995 – 31/3/2008 period, with a reference period of 1918-1989.
Figure 1 shows the daily anomalies calculated from this international data (see source below the graph). The average anomaly is -2.0 degrees Celsius, suggesting that El Alto is now substantially colder than it was during most of the previous century.
The international data thus shows even more cooling than the national data (-0.3 degrees for El Alto). This may have to do with the longer reference period, as the 1961-1990 period used by SENAMHI (and most of the IPCC work) was a relatively cold period. Indeed, in the 60s and 70s the media was making a big fuss about the World being on the brink of a new ice-age, because global temperatures were dropping and glaciers advancing almost everywhere (2).
|Figure 1: La Paz (El Alto): Average Daily Temperature Anomaly 1/1/1995 – 12/3/2008,
compared to average monthly temperatures for 1918-1989.
|Sources:For daily temperatures: Average Daily Temperature Archive, University of Dayton, GSOD weather station no. 852010,
located at 16.51667S/68.18333W, 4014 meters above sea level. For 1918-1989 average monthly temperatures:
The Global Historical Climatology Network, El Alto station located approximately at 16.50S/68.20W, 4103 meters above sea level
Note:Notice that the station for the historical data station apparently is located a 89 meters higher than the current station,
implying that the historical data should be about half a degree colder than the current data.
The average anomaly may therefore be biased towards zero by about half a degree Celcius
So, if you would like to study the impacts of climate change in Bolivia (and thus receive some of the benefits), be sure at least to get the direction of change right.
Is Bolivia cooling down? Leave your reply below.
Lykke Andersen is the Director of the Center for Economic and Environmental Modeling and Analysis (CEEMA) at the Institute of Advanced Development Studies (INESAD), La Paz, Bolivia.