Because thermal capacity of oceanic water is at least 5.000x higher, then this one of atmosphere, global mean temperature of atmosphere is much less relevant, then the global mean temperature of ocean. And this temperature is still raising in accordance to increase of carbon dioxide concentration, despite the weak slow down of warming of atmosphere in recent decade.
Other phenomena, like increase of global temperature of atmosphere aren't so relevant for GW, because they undergo El-Nina / El-Nino cycle and solar cycle due the wobble of center of mass in Sun-Jupiter system (because mean solar cycle is faster then Jupiter period, it's probable, some other planets are affecting it, too). The center of mass controls the direction of global current of plasma beneath surface of Sun, which affects the frequency of sun spots (i.e. magnetic bubbles in plasma, raising to surface) and solar eruptions. The charged particles of solar wind penetrating the atmosphere of Earth are serving like condensation nuclei of fog and snow and they're making Earth surface more reflective.
The effect of ocean heating is not so straightforward. In general, it increases the number of convective cells in our atmosphere and frequency of their switching in similar way, like during heating of water in open vessel. Note that this change increases continental character of the weather, so that above continents the global warming may even lead to temperature records on both sides of temperature scale.
At the moment, when convective circulation switches from horizontal to vertical, an ice age period may occur, because Earth becomes intensively cooled. This is forced by hysteresis, because snow-white surface of Earth becomes more reflective at the same time. Just after cooling of oceans (which takes some time due their thermal capacity) the warm period is restored. Here are some indicia, the start of ice age can be very fast (compare the disaster movie Day after tomorrow) and period of fast paced global warming had preceded this event in younger dryas period, so maybe we are facing ice age soon.
Concerning the hypothesis of man made global warming, it's proven statistically, people are making weather warmer and drier on per week basis (1, 2), so no further evidence is necessary - we can just extrapolate these weekend fluctuations to decades of years. During last warming periods the rise of carbon dioxide followed warming with delay of many decades with compare to present situation - so we can see this argument of many skeptics rather as another evidence for man-made origin of global warming. In addition, we can consider for example September 11, 2001 climate impact study. Measurements showed that without contrails, the local diurnal temperature range (difference of day and night temperatures) was about 1 degree Celsius higher than immediately before.
In my opinion, human activity started irreversible process, which couldn't be reversed so easily due the hysteresis described above. Nevertheless, we should save money from carbon dioxide taxes for faster research of alternative energy sources to replace fossil fuel as soon, as possible. This would be useful with respect to both prevention of ice age period, both prevention of another rise of carbon dioxide concentration. Carbon dioxide dissolves the shells of coral and plankton, thus destroys the fishing grounds and diversity of biosphere.
But the main risk of fossil fuel depletion is the global nuclear war for the rest of their sources. It's generally ignored, the reason of the recent oil & food price crisis was always lost USA war. These wars are very expensive and at the case of global nuclear conflict the things would get even way, way worse.
For example, for production of rice it's required 2552 m³ of water/ ton rice, whereas for production of one ton of poultry 3809 m³ of water its required. Therefore the consumption of poultry may sound like ineffective waste of water for someone - but the content of proteins in rice is ten times lower, then in chicken meat! This explains, why people from deserts in Chad or Mongolia are living from pasturage, instead of agriculture. I even suspect, farming is more ecological then the agriculture as a whole, providing it doesn't use agricultural products (which usually does). Methane released by cows on pastures is negligible with compare to amount of methane, released by annual decomposition of plants without cows.
"Those who do not think about the future, do not deserve to have one."