Fill in the Blanks 225-testOnline version 225-test by Farhad Key 1 oases eking unbearable punctuated cull represents remnant consequences diminished glaciers Three degrees does not sound like much but it a rise in temperature compatible with the global heating that occurred between the last ice age , some 15 , 000 years ago , and the warmth of the eighteenth century . When Earth was cold , giant sometimes extended from the polar - regions as far south as St Louis in the US and the Alps in Europe . Later this century when it is three degree hotter glaciers everywhere will be melting in a climate of often heat and drought , with storms and floods . The for humanity could be truly horrific ; if we fail to act swiftly , the full impact of global heating could us along with vast populations of the plant and animals with whom we share Earth . In a worst case scenario , there might - in the 22nd century - be only a of humanity out a existence in the polar - regions and the few remaining left on a hot and arid Earth .