evidence: This paradox has long been predicted by climate modelers, but only recently quantified in detail by satellite sensors. The new findings are providing a definitive confirmation on one important issue, but at the same time raising other questions. The good news for climate scientists is that the data on cooling aloft do more than confirm the accuracy of the models that identify surface warming as human-made. A new study published this month in the journal PNAS by veteran climate modeler Ben Santer of the Woods Hole Oceanographic Institution found that it increased the strength of the "signal" of the human fingerprint of climate change fivefold, by reducing the interference "noise" from background natural variability. Sander says the finding is "incontrovertible." [...] Early climate modelers predicted back in the 1960s that this combination of tropospheric warming and strong cooling higher up was the likely effect of increasing CO2 in the air. But its recent detailed confirmation by satellite measurements greatly enhances our confidence in the influence of CO2 on atmospheric temperatures, says Santer, who has been modeling climate change for 30 years.