What was done
The authors analyzed micro-charcoal, pollen and stable oxygen isotope (δ¹⁸O) data obtained from sediment cores extracted from two crater lake basins in central Turkey, from which they reconstructed synchronized fire, vegetation and climate histories that extend back in time more than 15,000 years.

What was learned
Turner et al. determined that "climatically-induced variation in biomass availability was the main factor controlling the timing of regional fire activity during the Last Glacial-Interglacial climatic transition, and again during Mid-Holocene times, with fire frequency and magnitude increasing during wetter climatic phases." In addition, they say that spectral analysis of the Holocene part of the record "indicates significant cyclicity with a periodicity of ~1500 years that may be linked with large-scale climate forcing."

What it means
In discussing their observations, the three researchers write that "a ~1470-year climatic periodicity was recognized by Bond et al. (1997, 2001) from the flux of ice-rafted debris in North Atlantic deep-sea cores." With respect to this latter finding, Bond et al. (2001) have written that "over the last 12,000 years virtually every centennial time-scale increase in drift ice documented in our North Atlantic records was tied to a solar minimum." And in light of this observation, Bond et al. (2001) concluded that "a solar influence on climate of the magnitude and consistency implied by our evidence could not have been confined to the North Atlantic," suggesting that the cyclical climatic effects of the variable solar inferno are likely experienced throughout the world, which implication is supported by Turner et al.'s evidence from the East Mediterranean part of the planet.

References
Bond, G., Kromer, B., Beer, J., Muscheler, R., Evans, M.N., Showers, W., Hoffmann, S., Lotti-Bond, R., Hajdas, I. and Bonani, G. 2001. Persistent solar influence on North Atlantic climate during the Holocene. Science 294: 2130-2136.

Bond, G., Showers, W., Cheseby, M., Lotti, R., Almasi, P., deMenocal, P., Priore, P., Cullen, H., Hajdas, L. and Bonani, G. 1997. A pervasive millennial-scale cycle in North Atlantic Holocene and Glacial climates. Science 278: 1257-1266.