We need safety and food and clean water and air to make a picnic possible. Relaxing summer get-away's benefit from having a park with shade and a restroom available. Feeling secure from danger is also needed for family fun or a romantic afternoon. Packing a picnic requires money for food or a garden with harvest ready produce. Clean safe drinking water and water to wash hands and dishes after eating is also a need for a nice time that is also better for the environment.
Packing reusable bottles of water is also more sustainable for helping preserve the environment for future picnics. Stainless steel bottles are long lasting and clear plastic recyclable bottles can be also be washed and reused. Clear bottles whether plastic or glass can also be used to sterilize water if left in sunshine for six to eight hours on a warm day.
For more about sterilizing water in reusable clear bottles see a TEDx talk by Kevin McGuigan, "Saving Lives with Sunlight:" (TEDxTalk, 2014), or a shorter video about use of the technique for daily water needs in Uganda: (NTVUganda, 2015).
A picnic table in a shaded pavilion can make any meal a nice break on a sunny or windy day.
Disclaimer: This information is provided for educational purposes