Okay. @ialocin made a note about Transients. By some odd reason, I have not come across this yet. Previously, I used to display counts by:

• jQuery (client side loading)
• Page caching (when storing counts locally)
• Cron updating count values
• And most recently, stored all counts in post meta and updated the meta every 100 loading of the page... pretty wild.

But no, there is something better. I lot better. Transients. Transients. Transients... chant it for hours... Once you've meditate and returned, delve into the following code which I customized for you:

// Check for transient. If none, then execute code
if ( false === ( $data = get_transient( 'trans_' . $post_id ) ) ) {

    /* action */
    $facebook_like_share_count = function ( $url ) {

        $api = file_get_contents( 'http://graph.facebook.com/?id=' . $url );

        $count = json_decode( $api );

        return $count->shares;
    };

    $twitter_tweet_count = function ( $url ) {

        $api = file_get_contents( 'https://cdn.api.twitter.com/1/urls/count.json?url=' . $url );

        $count = json_decode( $api );

        return $count->count;
    };

    $pinterest_pins = function ( $url ) {

        $api = file_get_contents( 'http://api.pinterest.com/v1/urls/count.json?callback%20&url=' . $url );

        $body = preg_replace( '/^receiveCount\((.*)\)$/', '\\1', $api );

        $count = json_decode( $body );

        return $count->count;

    };

    $google_plusones = function ( $url ) {
        $curl = curl_init();
        curl_setopt( $curl, CURLOPT_URL, "https://clients6.google.com/rpc" );
        curl_setopt( $curl, CURLOPT_POST, 1 );
        curl_setopt( $curl, CURLOPT_POSTFIELDS, '[{"method":"pos.plusones.get","id":"p","params":{"nolog":true,"id":"' . $url . '","source":"widget","userId":"@viewer","groupId":"@self"},"jsonrpc":"2.0","key":"p","apiVersion":"v1"}]' );
        curl_setopt( $curl, CURLOPT_RETURNTRANSFER, true );
        curl_setopt( $curl, CURLOPT_HTTPHEADER, array( 'Content-type: application/json' ) );
        $curl_results = curl_exec( $curl );
        curl_close( $curl );
        $json = json_decode( $curl_results, true );

        return intval( $json[0]['result']['metadata']['globalCounts']['count'] );
    };

    // store data in array
    $data = array (
        $facebook_like_share_count,
        $twitter_tweet_count,
        $pinterest_pins,
        $google_plusones
    );

    // Put the results in a transient. Expire after 6 hours
    set_transient( 'trans_' . $post_id, $data, 6 * HOUR_IN_SECONDS  );
}

if (is_array($data)) {

    $facebook_like_share_count = $data[0];
    $twitter_tweet_count = $data[1];
    $pinterest_pins = $data[2];
    $google_plusones = $data[3];

}

Firstly, make sure that $post_id is already set previously to adding this code as it uses the ID to add a unique handle to the transient.

We are storing cached data in the database temporarily by giving it a custom name and a timeframe after which it will expire and be deleted.

So, for every 6 hours, it updates the cached array. It's as simple as that. See the comments for clarification.

EDIT:

As per discussions in the comment thread, I have adjusted the code. Firstly, make sure you have the share functions inside your functions.php file (I believe you already have this in your current setup), then in your single.php file, add the following where you want to get the count values.

// get post id
$post_id = get_the_ID();

// get perm url to be used for share count functions
$url = get_permalink( $post_id );

// Check for transient. If none, then execute code
if ( false === ( $data = get_transient( 'trans_' . $post_id ) ) ) {

    /* action */
    $facebook_like_share_count ("$url");
    $twitter_tweet_count ("$url");
    $pinterest_pins ("$url");
    $google_plusones ("$url");

    // store data in array
    $data = array (
        $facebook_like_share_count,
        $twitter_tweet_count,
        $pinterest_pins,
        $google_plusones
    );

    // Put the results in a transient. Expire after 6 hours
    set_transient( 'trans_' . $post_id, $data, 6 * HOUR_IN_SECONDS  );
}

if (is_array($data)) {

    // these are your variables containing the share count
    $facebook_like_share_count = $data[0];
    $twitter_tweet_count = $data[1];
    $pinterest_pins = $data[2];
    $google_plusones = $data[3];

}

Please read the comments I put inside the code for clarification.