Some very nice graphics showing exactly what we send and where available here
http://atlas.media.mit.edu/en/profile/country/irl/
The "40%" figure relates to
food exports specifically.
http://www.irishtimes.com/business/...imary-driver-of-economic-turnaround-1.2221285
We are the 33rd largest exporter in the world, which may be as a result of many things that people have an issue with (multinationals driving high value exports for example) but is definitely not something we should either ignore or view as just a problem. 14% of our exports go to the UK - a not insignificant amount but compare that to Ireland in 1973 - the halcyon days that the 50 and 60 something English voted on the basis of - 55% of
ALL Irish exports went to the UK. Fundamentally, whilst they are still a large part of our customer base, we have extended our base beyond a dangerous dependence on them in all areas - even food. Following their lead would be to foolishly bind ourselves once again to a dependence on their magnanimity - it was never a good deal for Ireland.
A hard Brexit will hurt - that is pretty clear. And it will be a difficult adjustment - but if history has taught us nothing else it shows we have dealt with far worse from them.