How is that relevant? That coal plants deaths are spread over the entire world does not make them less lethal.

The deaths caused by Chernobyl is a tiny blip compared to coal no matter whose estimates you pick.

In 2010 alone, estimated deaths from US coal power plants alone was 13,000, with a huge number of other bad health effect (20,000 heart attacks for example) [1]

In the 3 decades from Chernobyl we can extrapolate to maybe ~350k-400k deaths from US coal plants alone.

The number of deaths due to Chernobyl on the other hand, is rarely estimated higher than the low tens of thousands. The number of cancer incidents attributable to Chernobyl is likely far higher. E.g. estimates of an excess 7k thyroid cancer incidents in Belarus, Ukraine and Russia by 2005. But only a small number of those have died of cancer so far (the number will likely increase, but the reduction in overall life expectancy is still modest).

In 2005, the UN predicted 4,000 deaths due to Chernobyl [2]. Greenpeace countered with a claim of up to ~300k deaths total[3] (based on a combination of an estimated 93k deaths in Belarus and 60k deaths in Russia due to cancers, and an additional estimate of potentially another 140k premature deaths in the following/coming years).

Even if we accepts the Greenpeace claims, as the upper boundary, more people have likely died due to US coal plants alone than due to Chernobyl in the years since Chernobyl.

And the US is not the biggest consumer of coal. Already well before 2000, China had surpassed US coal consumption. Tack on India and Russia, and the US coal consumption is only 1/3 of that used by the top 4 countries. Go to the top 10, and the US coal consumption made up ~25% by 2000, and as far as I know dropping as a percentage of overall consumption due to dramatic continued growth in places like China. So even just looking at the top 10, it would not be unreasonable to quadruple the estimates of excess deaths from coal from the above to 1.4-1.6 million in the 3 decades from Chernobyl.

But of course these plants were going for decades before that, and will continue for decades to come, and many of these countries have far more lax rules than the US when it comes to emissions. The reality is that worldwide deaths from coal likely are equivalent to Greenpeace's idea of Chernobyl every 2-5 years. On the other hand, if the UN predictions are right, US plants alone are as lethal as 3 Chernobyl's every year, and coal worldwide is equivalent to somewhere well above 12 Chernobyl's every year.

Now, it is reasonable to bring up that Chernobyl is only one plant, but the point is the difference is damage scenarios: Nuclear plants kill when something goes wrong, and something goes wrong exceedingly rarely, leaving us able to name the ones attributable to 90%+ of nuclear power related deaths.

Coal plants, on the other hand, silently kills every day, around the clock, during normal operation. Chernobyl, even accepting the worst case estimates, does not lift nuclear even into the same league. Even if we replaced coal with Chernobyl type reactors, with the same lax safety procedures as at Chernobyl, rather than opt for the much safer designs and processes that were the norm even back in 1986, we'd still kill far fewer people.

[1] http://www.rmi.org/RFGraph-health_effects_from_US_power_plan...
[2] http://www.slate.com/articles/health_and_science/explainer/2...
[3] http://www.greenpeace.org/international/en/news/features/che...