tropics appeared to be cooler
...that during hot greenhouse periods in Earth's history, the tropics appeared to be cooler than they are today?
...that during hot <a class="mw-redirect" href="./Greenhouse_Earth" id="mwhw" rel="mw:WikiLink" title="Greenhouse Earth">greenhouse periods</a> in Earth's history, the <b id="mwiA"><a href="./Cool_tropics_paradox" id="mwiQ" rel="mw:WikiLink" title="Cool tropics paradox">tropics appeared to be cooler</a></b> than they are today?