The current temperate change is between 0.01 and 0.02 degrees/year, two orders of magnitude greater than when the ice age ended. The problem isn't so much that temperature is changing but that it's changing so fast. The greater the rate of temperature change the harder adaption will be for both human and natural systems.
I've never been able to figure out the original of those claims - do you know? I can't find any scientific sources for it - on the contrary:
Until a few decades ago it was generally thought that all large-scale global and regional climate changes occurred gradually over a timescale of many centuries or millennia, scarcely perceptible during a human lifetime. The tendency of climate to change relatively suddenly has been one of the most suprising outcomes of the study of earth history, specifically the last 150,000 years (e.g., Taylor et al., 1993). Some and possibly most large climate changes (involving, for example, a regional change in mean annual temperature of several degrees celsius) occurred at most on a timescale of a few centuries, sometimes decades, and perhaps even just a few years. The decadal-timescale transitions would presumably have been quite noticeable to humans living at such times, and may have created difficulties or opportunities (e.g., the possibility of crossing exposed land bridges, before sea level could rise)
This is mildly interesting, but note that the paper has no citations later than 1998, and the paper itself is dated that year if you go up a level, so the research is not at all recent, but nearly 20 years old.
Also, there is a clarification at the top which reads:
This represents an earlier version of our text. Some changes have been made since we stopped modifying this web version: e.g. we have added a discussion of the role of volcanic aerosols in sudden climate changes...evidence suggests the rapid cooling at the end of the Eemian interglacial was due to a big explosive volcanic event. Other 'volcanic' cooling events occurred during the Holocene.
In other words, they are talking about abrupt (and transitory) volcanic events, not Milankovitch cycles. Moreover, volcanoes produce cooling, not heating (think of the various "years without summers")