One hundred years of climate change in Mexico

Abstract

Spatial assessments of historical climate change provide information that can be used by scientists to analyze climate variation over time and evaluate, for example, its effects on biodiversity, in order to focus their research and conservation efforts. Despite the fact that there are global climatic databases available at high spatial resolution, they represent a short temporal window that impedes evaluating historical changes of climate and their impacts on biodiversity. To fill this gap, we developed climate gridded surfaces for Mexico for three periods that cover most of the 20th and early 21st centuries: t1-1940 (1910-1949), t2-1970 (1950-1979) and t3-2000 (1980-2009), and used these interpolated surfaces to describe how climate has changed over time, both countrywide and in its 19 biogeographic provinces. Results from our characterization of climate change indicate that the mean annual temperature has increased by nearly 0.2°C on average across the whole country from t2-1970 to t3-2000. However, changes have not been spatially uniform: Nearctic provinces in the north have suffered higher temperature increases than southern tropical regions. Central and southern provinces cooled at the beginning of the 20th century but warmed consistently since the 1970s. Precipitation increased between t1-1940 and t2-1970 across the country, more notably in the northern provinces, and it decreased between t2-1970 and t3-2000 in most of the country. Results on the historical climate conditions in Mexico may be useful for climate change analyses for both environmental and social sciences. Nonetheless, our climatology was based on information from climate stations for which 9.4-36.2% presented inhomogeneities over time probably owing to non-climatic factors, and climate station density changed over time. Therefore, the estimated changes observed in our analysis need to be interpreted cautiously.

Fig 1

Location of weather stations used to generate climate surfaces of precipitation, maximum and minimum temperature for three periods: a. t₁-1940 (1910–1949), b. t₂-1970 (1950–1979) and c. t₃-2000 (1980–2009). Shaded areas represent mountainous regions above 1500 masl. Stations used were not corrected for inhomogeneities and densities vary between periods and climate variables. For t₁-1940 we used 803 stations for precipitation and 500 for temperature, for t₂-1970, we used 3411 and 3670 and in t₃-2000, 3870 and 4200 for precipitation and temperature, respectively.

Fig 2. Biogeographic regions and provinces of Mexico: Nearctic and Neotropical regions, and the transition zone.

Reprinted from [57] under a CC BY license, with permission from [CONABIO], original copyright [1997].

Fig 3

Seasonal change of maximum (♦) and minimum (bars) temperature from t1-1940 to t2-1970 (Δt₁-t₂) and from t₂-1970 to t₃-2000 (Δt₂-t₃) in the biogeographic provinces of Mexico. Negative values indicate a decrease in temperature from the previous period and positive values indicate an increase. DB: Depresión del Balsas, SMOr: Sierra Madre Oriental, DC: Del Cabo, C: California, Sse: Sonorense, SMOcc: Sierra Madre Occidental; AN: Altiplano Norte, T: Tamaulipeca, BC: Baja California, CP: Costa del Pacífico, AS: Altiplano Sur, EN: Eje Neovolcánico, GM: Golfo de México, O: Oaxaca, Y: Yucatán, P: Petén, AC: Altos de Chiapas, Ssc: Soconusco, and SMS: Sierra Madre del Sur. Stations used were not corrected for inhomogeneities and densities vary between periods, especially between t₁-1940 to t₂-1970. Biogeographic provinces reprinted from [57] under a CC BY license, with permission from [CONABIO], original copyright [1997].

Fig 4. Seasonal precipitation changes in % (♦) and millimeters (bars) from t₁-1940 to t₂-1970 (Δt₁-t₂) and from t₂-1970 to t₃-2000 (Δt₂-t₃) in the biogeographic provinces of Mexico.

Negative values indicate a decrease in precipitation from the previous period and positive values indicate an increase. DB: Depresión del Balsas, SMOr: Sierra Madre Oriental, DC: Del Cabo, C: California, Sse: Sonorense, SMOcc: Sierra Madre Occidental; AN: Altiplano Norte, T: Tamaulipeca, BC: Baja California, CP: Costa del Pacífico, AS: Altiplano Sur, EN: Eje Neovolcánico, GM: Golfo de México, O: Oaxaca, Y: Yucatán, P: Petén, AC: Altos de Chiapas, Ssc: Soconusco, and SMS: Sierra Madre del Sur. Stations used were not corrected for inhomogeneities and densities vary between periods, especially between t₁-1940 to t₂-1970. Biogeographic provinces reprinted from [57] under a CC BY license, with permission from [CONABIO], original copyright [1997].

Fig 5. Climate change in Mexico from t₁-1910 to t₃-2000.

Negative and positive areas represent downwards and upwards changes, respectively, in annual precipitation (Bio 12), maximum temperature of the warmest month (Bio 05) and minimum temperature of the coldest month (Bio 06). Blue areas indicate negative signs (decrease) for the difference between t₁-1940–t2-1970 and t₂-1970–t₃-2000. Red areas indicate positive signs (increase) for the difference between t₁-1940–t₂-1970 and t₂-1970–t₃-2000. White areas indicate that the sign between t₁-1940–t₂-1970 and t₂-1970–t₃-2000 were inconsistent. Biogeographic provinces reprinted from [57] under a CC BY license, with permission from [CONABIO], original copyright [1997].