I hadn't realized it was based on concrete measurements of what the paleoclimates, the ancient climates, were, as recorded in the ice sheets, as recorded in deep ocean sediments, as recorded in lake sediments, tree rings, and a lot of other ways of measuring temperature.
No me había percatado que era basado en medidas concretas que eran los paleoclimas, los climas del pasado, tal y como se registra en las capas de hielo, en los sedimentos del fondo del océano, en los sedimentos de lagos, anillos de árbol, y muchas otras formas de medir la temperatura.